Help with my 71' roadrunner

How's it going folks. I am new to the website and learning about mopars basically. I'm 18 and finished turning my 80' malibu in a street-strip car and really wanted a mopar (blame dad for that lol, 67 Dart GTS):grin:. Well I scored big and found the mopar I've always wanted that was taken off the road in 77'. This RM23 roadrunner is origionally a california car and is basically rust free and I talked the guy down from 10k to 7.5k. Has numbers matching 383 4 speed and the car is origional to the point of having the factory exhaust. What I'm trying to figure out is the differences and specs between a regular 383 and the "N" code HP 383. Mine just so happens to be the "N" code. Another question I have is how often did 71' roadrunners that had the 383 4 speed come with AC? This car has the AC as well. Finally, this car has what I believed is called a DictAphone (cassette recorder) and had the black bikini vinyl top, origional color curious yellow. Are these options rare on roadrunners?
There's just a lot of things on this car that shows that it was special ordered and not part of a bulk order made by the dealerships. Case and point, its a 4 speed with the bucket seats, console, etc. but has AC and has a Clock instead of the RPM Gauge. I'm not sure how rare the bikini vinyl top is either. But with the options this thing has, along with the dictAphone, I believe the origional owner was a doctor or something along those lines. He wanted to look badass in this thing with all the racing options but at the same time have the lucturies such as the AC, vinyl top, etc. As we all know, these things ordered in bulk were nothing but bare bone cars, and if any muscle car guy from back then ordered one of these, he wouldn't want the AC or other luxuries.
Unfortunately, this car did have the build sheet but a rat or mouse made a home underneath the back seat and made some nesting out of it. I saved whatever scraps were legible. Here's the fender tag codes:

first 7 vin # RM23N1G

V8X 26 END
M21 N41 N97 R36 V21
C55 G11 G36 H51 J45 L31
V4X U A01 A87 B11 C16
GY3 M6X9 TX9 610 040964
E65 D21 RM23 N1G

http://i113.photobucket.com/albums/n211/DarkSnipe5/Nov08069.jpg
http://i113.photobucket.com/albums/n211/DarkSnipe5/Nov08062.jpg
http://i113.photobucket.com/albums/n211/DarkSnipe5/Picture015.jpg
http://i113.photobucket.com/albums/n211/DarkSnipe5/Nov08061.jpg

Welcome. You've got a pretty cool car there, one worth a proper restoration (as opposed to hacking in to a race car). First, it's a 4 speed. Big plus. It's also a 'high impact" color. Also a plus. Then there is the A/C and the cassette. While you don't see tons of 4 speed cars with A/C, it isn't unheard of. The cassette on the other hand is a pretty rare option, and you're lucky it's still there.

As far as differences in 383s goes, a "lo-pro" would have had different exhaust manifolds, cam, valve springs, carb tuning and distributor advance curve. Do NOT let anyone try to snow you with that "magnum head" BS. A 383 2V had the exact same head casting as any of the 4V or Six Pack motors did.

Your fender tag reads from bottom left to top right (if you didn't know that already)


V8X transverse tape stripe, black
26 26" radiator
END end of the tag
M21 chrome drip rail moldings
N41 dual exhaust
N97 noise reduction package (probably a California car, no tips just turn downs)
R36 AM/FM Stereo w/cassette
V21 hood performance treatment
C55 bucket seats
G11 tinted glass
G36 dual painted racing mirrors
H51 A/C
J45 hood pins
L31 hood/fender mounted turn signals
V4X black vinyl roof
U sold car
A01 light package
A87 road runner decor group
B11 hd 11" drum brakes
C16 console
GY3 citron yella
M6X9 medium class bucket seat black
TX9 black interior paint
610 build date June 10, 1971
040964 order number
E65 engine code (383)
D21 trans code (4 speed)
RM23 N1G breaks down to road runner hard top 383 1971 St.Louis ass. plant

Welcome. You've got a pretty cool car there, one worth a proper restoration (as opposed to hacking in to a race car). First, it's a 4 speed. Big plus. It's also a 'high impact" color. Also a plus. Then there is the A/C and the cassette. While you don't see tons of 4 speed cars with A/C, it isn't unheard of. The cassette on the other hand is a pretty rare option, and you're lucky it's still there.

As far as differences in 383s goes, a "lo-pro" would have had different exhaust manifolds, cam, valve springs, carb tuning and distributor advance curve. Do NOT let anyone try to snow you with that "magnum head" BS. A 383 2V had the exact same head casting as any of the 4V or Six Pack motors did.
Your fender tag reads from bottom left to top right (if you didn't know that already)


V8X transverse tape stripe, black
26 26" radiator
END end of the tag
M21 chrome drip rail moldings
N41 dual exhaust
N97 noise reduction package (probably a California car, no tips just turn downs)
R36 AM/FM Stereo w/cassette
V21 hood performance treatment
C55 bucket seats
G11 tinted glass
G36 dual painted racing mirrors
H51 A/C
J45 hood pins
L31 hood/fender mounted turn signals
V4X black vinyl roof
U sold car
A01 light package
A87 road runner decor group
B11 hd 11" drum brakes
C16 console
GY3 citron yella
M6X9 medium class bucket seat black
TX9 black interior paint
610 build date June 10, 1971
040964 order number
E65 engine code (383)
D21 trans code (4 speed)
RM23 N1G breaks down to road runner hard top 383 1971 St.Louis ass. plant


Yeah, that was a little "creative license" the marketing department took when advertising the 383 RR and Bee engines as having the "440 Magnum heads." Not untrue as they were used on the 440 Magnums and Super Commandos, as Tem stated above, but they were also used on 383 2 barrels as well.

Do you know how rare the cassette is? I had another guy on a different forum telling me he heard that only 137 were put into RR's that year. Not sure if this is true or not but would like some verification. I know they sell for 1500 on eBay easily.
But I refuse to turn this car into a racer and will be going with a full factory restoration. May bump up the cam if the previous owner didn't already do that. He claimed he put one of the biggest mopar purple cams into it.
As far as the heads go, this one was the HP 4 barrel 383, so it should have the same heads as a 440 right? I also heard that the 440 and 383 HP shared similar cams and valve springs.

That looks like a pretty much untouched/unmolested car. I would think twice before I did a "restoration" on the car, especially if the paint is original. If it is I would hand polish it and them put a wax or poly sealer on it and leave it original as that speaks volume for the car and MANY people are very turned on by it.
I would shampoo the carpets, possibly re-die it and patch what appears to be the hole on the side of the trans hump next to the gas pedal.

Do you know how rare the cassette is? I had another guy on a different forum telling me he heard that only 137 were put into RR's that year. Not sure if this is true or not but would like some verification. I know they sell for 1500 on eBay easily.
But I refuse to turn this car into a racer and will be going with a full factory restoration. May bump up the cam if the previous owner didn't already do that. He claimed he put one of the biggest mopar purple cams into it.
As far as the heads go, this one was the HP 4 barrel 383, so it should have the same heads as a 440 right? I also heard that the 440 and 383 HP shared similar cams and valve springs.

You must LISTEN young Padawan if you wish to learn:grin:

A 383 2 barrel and a 440 Six Pack have the EXACT SAME HEAD. A 383 4V and a 440 4V (the "magnum" motors) used the exact same cam and valve springs. And before you ask, they had the exact same valves, as did a 383 2V etc etc etc.

I doubt anyone including Galen knows exactly how many were built with the cassette, but it's safe to say it wasn't many.

I also agree with Darryl IF that is the original paint, and IF there are a ton of usable pieces (rear seat, passenger's seat etc) then I wouldn't replace them for the sake of replacing them. The original stuff is better for you in the long run.

As far as the cam goes, something tells me this guy was blowing smoke. I'm betting it doesn't have "one of the biggest purple cams" available.

Assuming you want to run your cast exhaust I can set you up with a cam that will make it go like stink, idle easy, and be a pleasure to drive. It's the same cam I ran in my Certified Stock Six Pack Challenger and I was running 12.80s @110.6 with no traction, but was deceptively sedate and easy to street drive.

Something else about the heads. Your car being a 71 will probably have either 346 or 452 castings (as opposed to 906s) They are good heads. No need to change. YES, the port configuration is slightly different than a 906, BUT there is a give and take here.

Yes, the 346/452 heads have a slightly flatter intake port than a 906. BUT, they have MORE short side radius on the exhaust side than does a 906. So you loose a little on the intake side, but GAIN a little on the exhaust. A fair trade in my book.

Also, the 452 has induction hardened exhaust seats in them (346s are the same head except for this. NO hard seats). But since this is a simple induction hardening and NOT a hard seat installed in the head, you will loose the hardness when you do a valve job. Best thing at that point is to have hard seats installed (and I also go with bronze guides) and you're set for crappy gas.

You are young enough that you may not understand the value of the heads Tem is explaining above. The older heads that didn't have the hardend seats need to have them added to run unleaded gas, so it is money you don't have to spend.

The problem with leaving the car alone is that the yellow you see isn't the origional color. Some jack*** used yellow spray paint. The next problem is the origional owner screwed up both quarters. The driver side quarter I believe is workable, but the passenger side not so god. There was at least 2 inches thick of bondo on the passenger side, which tells me this guy was t-boned. The frame is good and if i remember right they replaced the door with a 71 charger door.
The interior is going to need to be re-worked. The headliner was sagging and I already took that out and the seats need to be re-upolstered. Now with the motor, the guy was claiming that it had a 525 lift. I doubt this is true but we'll see when I fire it up.
Now concerning the heads and motors etc. , I'm still learning a bit but as far as restorations go, this isn't my first rodeo. Just got finished with my 80' malibu and finishing dad's 67' Dodge Dart GTS. Here's some pics:

http://http://i113.photobucket.com/albums/n211/DarkSnipe5/DartinOct08001.jpg
http://http://i113.photobucket.com/albums/n211/DarkSnipe5/Dartmovie017.jpg
http://http://i113.photobucket.com/albums/n211/DarkSnipe5/Nov08047.jpg
http://http://i113.photobucket.com/albums/n211/DarkSnipe5/Nov08042.jpg

Isn't your first rodeo, but don't know if a 383 and a 440 use the same head.

Links weren't workin for me

Sorry bout the links man. Like I said I'm still learning the mopars I learned off dad's dart's 440. Plus my first resto was a chevy which didn't help matters much but was still a good learning experience. Sounds like i'm gonna end up pullin the valve cover to check the numbers.

If you're planning on driving the car a bunch, I'd consider doing a rebuild on the motor so it can live on bad gas anyway. You will find out then which heads it has and can go from there

Sweet car! like runner said, one worth a proper restoration, that is a great car (wish I had it!) Keep us updated on progress!

Of course. I'm gonna restore this thing to factory specs. The only thing I'm considering about doing is converting those big a** drums in the front to A body disc spindle for safety purposes. I've heard plenty of scary stories about drums.

Of course. I'm gonna restore this thing to factory specs. The only thing I'm considering about doing is converting those big a** drums in the front to A body disc spindle for safety purposes. I've heard plenty of scary stories about drums.


The Mopar 11" drum brakes will stop that B body just fine, but you don't want to do 2 or 3 panic stops in a row or you WILL get a lot of brake fade on the second stop and will only have about 25% on the 3rd.

You just need to make sure they are in good working order, adjusted right, and assembled right. Many people mistakenly reverse the brake shoe position which effects there braking ability.

What Darryl said. The 11" drums on my Challenger would stop it just fine from 110+ at the end of a quarter mile. That said, they wouldn't be my choice if I wanted to go to Watkins Glen

I might just keep the origional drums on the front. Just depends on if I like them or not when I take it for a ride. I would just feel better with discs but that's just me.

If you swap to the A body setup (F body - Volare, Aspen, etc. parts work too and may be cheaper/easier to find) keep your old drum parts. That way you can always go back if you want, and if you sell it someday to a purist having the original parts can only help the sale.

Don't ask him how he knows that:grin:

hi the 71 383 hp 383 2bbl heads are 346 71 440 hp 440 4bbl 6bbl 71 440 not hp 346 so the head s are same ones

the springs on a 383 hp are red with a dampers which are called magnum springs. The 71 440hp 4 & 6 bbl use hemi springs with damper s which are black and heavy duty rockers. That's the difference. the 71 383 2bbl and 440 not hp have green springs no dampers:grin:

I know someone who might be looking for a black 70 RR bench with silver trim and a 4 spd.
None air grabber hood and trunk lid.
Oh and front drums too.

lol

I've found over the years that the best disk set stock. Is from a 73 to 79 B body. The spindle is about a half inch higher on the knuckle than a 66 to 72, but. It gives you more caster and camber adjustment and lowers the front a half inch. Of course you can get that back with your T bars.
Be sure what ever you go with to get the master cylinder and portioning valve. The 10 psi of brake pressure that stays on a drum wheel cylinder will fry disc brake pads.

I've done a lil more researching on the car in the past couple months.

The car has the 346 heads and am debating over rebuilding them or buying a set of 915 aluminum complete heads that were in a magazine for $900.

Second, I need to know which disc brake spindles will work on my 71'. The problem I've found is that starting in 72', B bodies got this rubber biscuit in between the k-frame and frame. This makes the disc spindle taller than those of 71' because they didn't have this rubber piece there. From what I've heard, If I used this spindle, it would throw off the whole front end and fry my ball joints.

Another thing, I have been looking at the codes on the fender tag and have figured out most of them. The codes that I cannot find are what wheels the car came with, if it was a sold car/bank/ etc., rear end code, and a few others. Is there somewhere else on the car to look for codes?

Finally is there any way that chrysler or another group has saved information on these cars. The build sheet in this car is in pieces from that stupid mouse nesting in the back seat. I've taken out the headliner and carpet and have found no other sheets.

There won't be a code for wheels on the fender tag, even if it had an optional wheel on it from the factory. Only place to find that is on your mouse-riddled build sheet.

The 346 heads are as good as anything else is. But if you're planning on DRIVING this, then you will need to have hard seats installed (bronze guides are nice too). I ran them on my 69 383 Bee and had no problems. Went consistent 13.50s (with a best of a .42 @103.2) with them and the motor was really mild.

Thanks for that bit of info. I was curious whether the 346 heads had the hardened valve seats so that answers that question. When I first got the car, it started right up but we weren't sure if it had those seats so we only ran it for two to three minutes. Would there be a benefit if I did go with a larger valves and those bronze guides? People dog the 346 heads over on Moparts because supposedly there an emission head and open chamber crap.

As far as the rims, what did most roadrunners come with? I just contacted the Chrysler Historical Collection last night in an attempt to find a copy of my build sheet along with any other info.

A 346 is the same as a 452 except for the induction hardened seats, which you will probably lose if much work needs to be done to the seats during a valve job. As far as bigger valves goes, there is no need for them unless you're going for a lot of power and more than 6000 rpm (in a 440). My (ex) six pack Challenger was making 419 to the rear wheels and had stock size valves (it was a certified pure stock motor). Car ran easy 12s on repop Polyglas tires. So why do you need more?

As far as wheels goes, I would guess that lots of 71s came with Ralley wheels. They were very popular, but also expensive (at the time). Was the same with the E body cars. Ralleys were really popular. But my Challenger (which was a real 440 Six Pack R/T) originally had 14" road wheels (magnums). Bottom line is there really isn't much tellin. I didn't put Ralleys or road wheels on my just to be different.

The main idea of the build is to keep the car looking very stock and clean up the heads and put in a mild cam. I was looking at the 484 mp grind, but a friend of mine who built mopar race motors back in the 60's and 70's suggests that I go with the 474 grind due to the 4 speed and my intentions of keeping the factory AC. Supposedly it'll keep the car a nice driver and still get me over the 425 hp rating i'm hoping to achieve.

With the rims, I was thinking a nice set of steelies with dog dish hub caps would keep that simple aggressive look but then I saw a nice set of magnums that would be really nice. I guess there's a company manufacturing 17x8 magnum rims and other mopar rims.

IF you're wanting to keep it looking "original", then I'm guessing you're not running headers. And if you're not running headers you don't want to run that cam. I doubt it will make 425hp anyway. If you're running manifolds then you should run the same cam I had in my Six Pack. IF the magazine that did the recap on the races figured things right, then I was making well over 450 at the flywheel......with a "stock" cam and 906 heads.

just a thought

I have the hi-po manifolds, which is a good plus. I planned on opening them up with a burr and running a 3in. exhaust in order to help compensate for the manifolds. Just kinda sucks because the factory exhaust and mufflers are on the car and just have surface rust. The pipes are solid and I believe they're 2 1/4 pipe.

Then don't change or alter them. You don't need to. My manifolds were unaltered, except for the flap for the heat riser was removed. I was running TTI 2.5" mandrel bent with Walker mufflers tho.:giggle:

I ran a best of 12.800@110.6 on those Polyglas tires getting NO traction. Weighed 3960 with me in it too.

BigBlockDart.com has all the info on the later B car spindles.

Hey Pat, great Car. Build it the way you want it. Just take the time to do it correctly. Take a look at the year one F.A.S.T. type cars. It just might catch your interest. Good luck.

[QUOTE=patmckinneyracing;26919]I've done a lil more researching on the car in the past couple months.

The car has the 346 heads and am debating over rebuilding them or buying a set of 915 aluminum complete heads that were in a magazine for $900.

Second, I need to know which disc brake spindles will work on my 71'. The problem I've found is that starting in 72', B bodies got this rubber biscuit in between the k-frame and frame. This makes the disc spindle taller than those of 71' because they didn't have this rubber piece there. From what I've heard, If I used this spindle, it would throw off the whole front end and fry my ball joints.

the 70 -72 disc spindle are the same ones as the 70 - 74 e-body

the tall ones are from 73- up
the 1973 cars are from aug 1972 - june 1973
1972 cars are aug 71- june 1972
1972 b-body cars do not come with rubber biscuit the 1973s do:grin:

U sold car ? on the tag

U- USA built to U.S. specs.
c can built to Canada specs
I int built to export specs

Nice bird.
as for the wheels a lot of guys in the 70's put Keystone classic's on their cars. They were very close to the magnum but a little more stylish. I've got them on my 71 and I get a lot of compliments on them.