452 build help

[plymouthman]

Hello all. I'm new here and am putting together a 73 roadrunner. I'm basically at the engine stage and would like some advice and or opinions.
The platform is a 69 440 block and stock steel 69 crank.
.060 over bore
speed pro flat top pistons
915 heads (gasket matched, polished & milled to level )
.507 .510 comp cam springs & lifter kit ( Dur @ .050: 240 246 lobe sep: 110.0 )
Offenhauser,360 single 4 tunnelram
Holley 750 race carb (list 9379)
Headman headers 1 7/8 tubes 3"collectors
8.75 rear - 4:11 posi
Manual steering
Power brakes
Car is all original , not all cut up
With the added weight of a roll cage , frame ties & ladder bars
Car is mostly gonna b a weekend cruiser (car shows and just cruise nite , but will see the track occasionally . Possibly even a light to light encounter
Would like to know what every one thinks of this combo , power potential and or anything I'm missing or should change or add.
Everything listed i already have just haven't started it yet
Thanks in advance

 

[747mopar]

I don't know.....4:11s and a tunnel ram for a weekend cruiser??? If wanting a cruiser I'd at least run 3:55s and a little friendlier intake (dual plane) but that's just me. I started out with 3:55s in my car and like them but I do to much freeway driving and the 3,100 rpm hauls are getting old so I'm dropping some 3:23s in it very soon. Just be sure what you are going to be doing with it and build it for that.

 

[plymouthman]

Thank u. I also meant to add that it will be backed by a 727 torqueflite and the tire size is 29x11.5 .
It won't be driven on the interstate.

 

[747mopar]

I see, I'm not a pro like some of these guys but I would think that setup should be good for 500+ hp and with your gearing you could go bigger on the cam provided the heads are done to handle it and you put the right stall converter in it. I had a set of iron heads done up for my build and that was the worst mistake I made not that they don't work great but by the time I was done I wasn't far from the price of the Edelbrocks which would have been a better head all the way around (you live and learn).

 

[plymouthman]

Well I would love to get a set of aluminum heads but not in the budget right now. I traded a guy some pays he needed for these heads 915 closed chamber , so I'm not really put any cash unless u figure in the grinding stones to gasket match .they were already cleaned up , I did the gasket matching . I Figure I can run them for awhile and when I get the extra cash and wife says i can spend the $ I will upgrade.

 

[Garys1969RR]

Sounds like a good start. The intake may be too much for it. I would think a Performer RPM would work better for street use. I have a similar build, 451 with 915 heads, 509 cam, 242 @ .050, Holley Street Dominator intake, alot more compression than you have. The thing flies! And has really good low end torque.

 

[plymouthman]

I'm not really looking for perfect street manners and kinda want to stick with the tunnel ram, I already have the intake and besides the original hood already has a hole cut in it ( was their when I got the car) besides the tunnel ram cool factor is of the charts. Bit at the same time it can go either way. It's not in stone what intake I have to use. Am wondering though if using the tunnelram is my carb sufficient ? Also haven't opened up the 440 yet so if it's all good and can use the factory rotating assemble will that be sufficient using the tunnelram

 

[GTX MATT]

I'd just run a good single plane or an Eddy RPM. From what I've read/heard the Offy tunnel rams aren't going to give you much more anyway. You may have trouble getting the carb dialed in on that too unless you have access to some A/F reading tools. You will probably need to do alot of tweaking to get that set up right. If you really want a tunnel ram get a Weiand with 2 Holley 660 Center Squirters, those are tunnel ram specific carbs.

Other than that it sounds like a solid build. Will need 2500+ stall for best performance. Also go with pistons from Wiseco or Diamond or another company. For about 50-75 bucks more you can get a much higher quality, much lighter weight, modern piston. I think I paid 550 for my Wiseco Pro Trus.

 

[Garys1969RR]

On the intake manifold test that a magazine ran, the Weiand tunnel ram made the most power, and also had real good low end torque. Don't remember if they ran 2 660 s on there or what. But if you are going tunnel ram, the Weiand with the 2 Holleys on top will work great as Matt said.

- - - Updated - - -

These are all suggestions of course, sometimes we have to start with what we have just to get a motor running, and a place to start from. The Offy will work ok, but there are better options.

 

[zyzzyx]

I used to race in the 70's and we found that a car that weighed less than 3000lbs could be made to run with a tunnelram. anything heavier, and the magic of it's design goes away. Sorry,
but I agree that the best bang for your buck is a single plane with an 850 on it! The tunnelram looks nice, but it doesn't work on a heavy car. Good Luck!

 

[GTX MATT]

Oh and on the power I'd say around 450 depending on how well the heads flow and assuming 10:1 compression.

 

[plymouthman]

Ok , it seems as though every one is against tunnelram. Well sorry yall , at this point that is all i have. I have 2 tunnel rams. A single for and a dual 4. Other than a couple factory iron intakes . Would I b better off running the dual with 2 750 race carbs. I didn't mention them because I really didn't want to go through the pulling teeth of tuning them. And the 915 have the big valves and have been gasket matched (intake & exhaust) so they should flow fairly decent being iron heads.
Kinda just wanna run what I have for now till I get get better , die to $ just not their right now and machine work just to bore (with deck plate) , hone , line hone , clean install cam bearings . Is like $1,100. And if memory serves me right. The 73 roadrunner is like 3800 lbs plus the roll cage, frame ties & ladder bars ,,, I'm putting it at roughly 4100 lbs (I'm guessing)

 

[Longroof]

What torque converter are you planning to run?

 

[plymouthman]

3500

 

[zyzzyx]

O.K., So two 750's on an engine with iron heads that can't flow anywhere near 800cfm maybe? You asked, and we're just trying to help!
I was young once too. You'll figure it out. Have fun!

 

[plymouthman]

I'm not a kid , and I realize that you all are trying to help. I don't know, that's why I'm asking. No need to be smug about it . Who old just like to run a tunnel ram. That all.
What wouldi need to do to make it work too your standards of perfect then ?

 

[Bigal75]

I would use the dual carb tunnel ram instead of the single. I've heard they have distribution issues. I would say this set up would make around 450-475 hp. Looks like an old school combo. Not ideal but it will be ok.

 

[IQ52]

Ok , it seems as though every one is against tunnelram. Well sorry yall , at this point that is all i have. I have 2 tunnel rams. A single for and a dual 4. Other than a couple factory iron intakes . Would I b better off running the dual with 2 750 race carbs. I didn't mention them because I really didn't want to go through the pulling teeth of tuning them. And the 915 have the big valves and have been gasket matched (intake & exhaust) so they should flow fairly decent being iron heads.
Kinda just wanna run what I have for now till I get get better , die to $ just not their right now and machine work just to bore (with deck plate) , hone , line hone , clean install cam bearings . Is like $1,100. And if memory serves me right. The 73 roadrunner is like 3800 lbs plus the roll cage, frame ties & ladder bars ,,, I'm putting it at roughly 4100 lbs (I'm guessing)

It's not perfect but it will certainly run good enough for you to have fun with it. You may be a little low on vacuum for the power brakes. When you want to go faster, come back and let us know.

 

[plymouthman]

I was already figuring i would have to run a vacuum booster anyway using that cam, wouldn't I ?? Anyway I apologize for seeming to b thick skulled (I guess i can be)
what is the tallest intake that you guys would recommend . I already have the street scoop and the hole in the hood. Not trying to waste $ not using a part that I bought and really don't want to tackle cutting up a second roadrunner hood just to fill that hole. Would rather use it. My good good has the hole cut in it. My second good has a good skin but serious cheese on the under side . I don't have to have the whole carb sticking out of the hood but Atleast the scoop would b nice.

 

[Garys1969RR]

The key to a good running motor is matching the components to all work together. You can still use the hood with the hood scoop on it with any height intake you want. I use the Holley Street Dominator intake, and it works very well. And it is low profile. The Victor intake works real well, and it is taller than most. But there again you need the cam, heads, and carb to match its power range. Also consider this: using a 1"spacer on most intakes can be worth another 15 to 20 horsepower at certain RPMs. Start with what you have, and then make a change when you run across a lower profile intake at a good price. They are easy to change, and then you can get a feel for what works best for you. I like to experiment with different combinations. The results sometimes surprise me.