• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

73 Roadrunner Clone with 5.7/545rfe (very pic heavy)

My Gen 3 swap thread… Its been a journey that isn’t quite over yet!

*Get through the primer and it will quickly get to the meat and potatoes!*



I started with a 1973 Plymouth Satellite. It is a factory A/C car with a factory 318. It ran and drove (albeit not well) I am pretty sure the main bearings on the engine were out and the valve guides as well… it smoked more than a 1970’s nascar fan… But it was a long time California car with perfect floors and what I thought was a great body!

View attachment 56940873 roadrunner project by rescuediver1982, on Flickr

View attachment 56941073 roadrunner project by rescuediver1982, on Flickr

View attachment 56941173 roadrunner project by rescuediver1982, on Flickr



So off I went, first I decided to tackle the body because I knew my Gen 3 swap was gonna be costly and I wasn’t sure how exactly the best way to do it was…

I had the body dustless blasted after I found some nasty looking filler in the rear quarters. For what it is worth, I like the simple, quick, nondestructive process of the dustless blasting but be warned. That crap get everywhere! You will find caked on glass sand in every nook and cranny ever created by those ma mopar engineers!

View attachment 56941273 roadrunner project by rescuediver1982, on Flickr

View attachment 56941373 roadrunner project by rescuediver1982, on Flickr



I found out the rear quarters had been wrecked pretty good, but they don’t make swap quarters or patch panels for the sections I needed… So off to pull out some metal, massage steel, and bump them back into shape. With some filler, some primer, some more filler, and finally more primer. In the process I deleted the radio antenna and the fender mounted turn signals. (some people may not like that idea but I didn’t like the square turn signals on the nice rounded body...)

View attachment 56941473 roadrunner project by rescuediver1982, on Flickr



View attachment 56941573 roadrunner project by rescuediver1982, on Flickr



View attachment 56941673 roadrunner project by rescuediver1982, on Flickr



Ohh… and this cool OE RR hood from a swap forum on FB! It was in pretty good shape!

View attachment 56941773 roadrunner project by rescuediver1982, on Flickr

View attachment 56941873 roadrunner project by rescuediver1982, on Flickr

View attachment 56941973 roadrunner project by rescuediver1982, on Flickr


Very cool build.
What trans did you use? I’m building a Superbird tribute and bought a wrecked 2016 challenger RT for the 5.7 Hemi, but it has an 8 speed that everyone is saying won’t work.....
Please advise
 
Hey Rescuediver, have not heard from you on your build since Feb. Hopefully you have completed it by now. Any updated pics?
On another note, I was wondering how you are getting along with that Corvette fuel regulator. I know Bouchillon uses them and it was part of a kit I bought from them for my 6.1 build. I'm not sure if mine was a faulty part or not but my car was surging at light throttle like the throttle body didn't know what to do. It felt like the throttle body was opening and closing. When I had it dynoed we noticed that it was running lean. I didn't like not knowing what the fuel pressure was so eliminated the Corvette part in favor of an adjustable regulator with a gauge. The Hemi likes 58psi so when I got it adjusted to the correct pressure, it fixed all of my fuel issues. Maybe my car just didn't want any GM parts on it but I'm glad I changed it out. Anyway, you are probably busy enjoying running the wheels off you new toy but we would like some updated pics when you get a chance.
 
Very cool build.
What trans did you use? I’m building a Superbird tribute and bought a wrecked 2016 challenger RT for the 5.7 Hemi, but it has an 8 speed that everyone is saying won’t work.....
Please advise
I have just searched online for 20 minutes with no success for you! I found a post where Chris at Hotwire had a ZF8 in the shop and they were working on it a while back but their website isn't updated yet! Sorry I am no help there! I used the 545RFE and my hotwire harness had everything I needed to simply plug it in. It doesn't need wheel sensors like the NAG1 does it just runs two speed sensors built on the trans itself.
 
Hey Rescuediver, have not heard from you on your build since Feb. Hopefully you have completed it by now. Any updated pics?
On another note, I was wondering how you are getting along with that Corvette fuel regulator. I know Bouchillon uses them and it was part of a kit I bought from them for my 6.1 build. I'm not sure if mine was a faulty part or not but my car was surging at light throttle like the throttle body didn't know what to do. It felt like the throttle body was opening and closing. When I had it dynoed we noticed that it was running lean. I didn't like not knowing what the fuel pressure was so eliminated the Corvette part in favor of an adjustable regulator with a gauge. The Hemi likes 58psi so when I got it adjusted to the correct pressure, it fixed all of my fuel issues. Maybe my car just didn't want any GM parts on it but I'm glad I changed it out. Anyway, you are probably busy enjoying running the wheels off you new toy but we would like some updated pics when you get a chance.

I had a bit of slump for a minute and stopped to LS swap a '77 C10 for my 16 year old son, It is an absolute blast to drive. Then I had to wait on my friend Nathan to finish his swap in his sick twin turbo 52 Buick before we could park mine on the lift! So starting last week have been putting everything back together and we have it running again. I am getting ready to order a drive shaft and then I will let you know how the corvette regulator is working under some load. As of now its idling and revving well. I know Nathan uses them on all his swaps and he does late model swaps exclusively. My buddy's 6.1 swapped Coronet has one and it has been running well for several years and done two full Hotrod Power Tours.

What kind of power numbers did you get on the dyno and what did you tune yours with?
 
Aaaannnndddd, I'm back at it! So here is what has happened:

The stock '73 bumpers were the first year of the wonderful new DOT standards that required the 5mph crash bumpers, so I thought they stuck out way further than I liked. So I brought the back bumper in about 1.25 inches and the front bumper I tightened up about 1.5 inches! I am much happier with the fitment!

I wish I would have taken a before picture of the back bumper but I had forgotten in on one of my sleep deprived states. To bring the bumper in, I actually shortened the mounting brackets. I made a "jig" of sorts out of all thread and a nut on each side of the base plate of each bracket to hold it up. I then scribed a 1.25 wide swath and cut it out. Used the nuts to lower the top plate down and hold it in place (still square mind you) and tacked it back together.
Before:
30640865667_322120bd08_k.jpg

During:
45582022871_e0f4fb6b04_k.jpg

After:
45582038671_8dfa0e3982_k.jpg


43764598800_2ead784a3b_k.jpg


The front was actually extremely easy. I figured out the front bumper is mounted to two bracket that bolted in two spots to the side of the front subframe. One bolt is in a slide slot and the other is simply a bolt hole. To slide it in, I simply extended the original slot and drilled a new bolt hole about 1.5" in.

Before:
45532122652_5b0576b5e0_k.jpg


After:
44668133775_ebaccfabaa_k.jpg
 
I got the bumpers where I wanted them but they had several years of dings and dents in them so I decided to paint them. Now I know the purists will not like them but, hey I do, and its mine! :lol:
So it got a full shave job and the bolt heads got deleted!
Front:
30640889247_7e6c8649dc_k.jpg

44668133715_d232c8c3a0_k.jpg

45582055311_57c52dbfc7_k.jpg

30640864017_687952f495_b.jpg

And Back:
45582048011_89966c9945_b.jpg

45582037861_d83471d2cd_b.jpg


After smoothing it all with 80 grit on the DA, came black epoxy primer, dolphin glaze, high build polyester primer, and finally a coat of catalyzed John Deer Blitz Black on all of the bumpers, trim, and door handles! They satin black finish turned out exactly how I wanted. I think it pops with the Sublime Pearl Green!
45531503252_df8e8513ea_k.jpg

30640877707_6774923395_b.jpg

43764590610_9f4c2568f5_k.jpg

45582044791_eb68d61c27_k.jpg

45582052541_9c236a8c36_k.jpg

45582034401_0b9d316b5a_k.jpg


Final product:
31709739008_06382bfb51_k.jpg

45582039011_b676e78038_b.jpg
 
So this is the point in the story where things take a turn for our hero... I had put tape on a section of the rear quarter where the rear bumper was going to protect the paint. When I lifted the tape, some of the paint came with it. I'm not sure why, but the paint didn't stick in that section and was peeling easily. So using a plastic scraper I started peeling until the paint started to stick. It seems the lifting is contained to the back half of that quarter. My only thought is with the tight space in my full garage, that I got somehow got oil or silicon in the primer that the wax and grease remover didn't take off.
Started as this:
31709752948_46d5c268a7_k.jpg


And went to this:
30640886457_8dfd2fbf41_k.jpg


But the good part of this story is I learn a new skill, how to blend paint and flow coat! lol
 
So moving on, Nathan calls and says the Buick is done can I have the car at his place the next day. Fast forward to:
45582036831_e91b14ed13_k.jpg


and 24 hours later, the 2009 5.7 Hemi with 50k miles has been placed back on its rightful perches atop its throne of a k-member! Everything had already been mocked up and working once, so now its all just final assembly. I snapped some photos of clearances and random things for people to check out that I hope may help others in the future!

Low mount alternator clearance, mainly notice the dimple we added to the shock tower to make sure it flowed around the alternator.
45582049111_5670517226_k.jpg


The low mount AC compressor on the driver side fits nicely after K-member perches were cut off and moved backwards.
45531494512_3d798be4fd_k.jpg


Used sticks of the copper allow tubing from O'reillys for trans cooler lines with compression fittings from Bouchillons to attach them to the trans. The cooler is built into my Champion swap radiator.
31709754428_83bf24996f_k.jpg


Used a universal condenser that nearly perfectly covers the opening to the radiator. All the AC Cold hose ran and mounted. I just used black POR15 on the outside of the core support to hide it when the grill and bumper is on.
31709749818_c4017c6fb6_k.jpg


The relays for the trinary and dual fans are mounted on elevator bolts under the front nose piece. It controls fan speed (high/low) for both fans in combination with engine temp and AC pressure.
45531490052_643f92175e_k.jpg

45531502092_6746e208c0_k.jpg


Ran the AC cold hose through grommets in the core support and up inside the inner fender before coming out by the blower motor.
44857160314_831f30d857_k.jpg


Another pic of the modified trans mount. basically plate steel with a hole drilled for a standard GM trans mount. (Bolts up really nicely to the 545RFE)
30640873307_066147a50c_k.jpg


45582029711_38f555d464_k.jpg


45582053381_515963dff0_k.jpg


And finally the intake put back on and it runs!
45581944921_6ab8d38301_b.jpg
 
What kind of power numbers did you get on the dyno and what did you tune yours with?[/QUOTE]

The dyno really didn't do much for me other than show the lean condition. As for any numbers, the problem we had with the 545RFE trans and my factory 68 shifter, the way it is set up I can turn off the overdrive which is 5th gear. I am unable to turn off 4th gear so when I have the shifter in drive, it will shift into 4th gear. The dyno shows true Rear wheel HP in the 1:1 ratio which is 3rd gear. 4th gear is .75:1 and with that in mind, it was showing 329 ft-lbs of torque @ 4800 rpm and 325 HP @ 5500 rpm. Not sure what the true numbers would be in 3rd but it ran mid 12's at around 106 on the dyno. Low 13's at about 100 with street tires at the strip. I have since put a Diablo tune in the factory computer it but have not driven it much since. It does seem to have a bit more power and maybe a little better fuel mileage. I checked the mileage after a 300 plus mile trip with a combination of road miles and city driving along with a couple full throttle bursts that I can't seem to avoid and got just short of 23 miles per gallon so I am very happy with the performance.
 
What kind of power numbers did you get on the dyno and what did you tune yours with?

The dyno really didn't do much for me other than show the lean condition. As for any numbers, the problem we had with the 545RFE trans and my factory 68 shifter, the way it is set up I can turn off the overdrive which is 5th gear. I am unable to turn off 4th gear so when I have the shifter in drive, it will shift into 4th gear. The dyno shows true Rear wheel HP in the 1:1 ratio which is 3rd gear. 4th gear is .75:1 and with that in mind, it was showing 329 ft-lbs of torque @ 4800 rpm and 325 HP @ 5500 rpm. Not sure what the true numbers would be in 3rd but it ran mid 12's at around 106 on the dyno. Low 13's at about 100 with street tires at the strip. I have since put a Diablo tune in the factory computer it but have not driven it much since. It does seem to have a bit more power and maybe a little better fuel mileage. I checked the mileage after a 300 plus mile trip with a combination of road miles and city driving along with a couple full throttle bursts that I can't seem to avoid and got just short of 23 miles per gallon so I am very happy with the performance.

Wow... that's awesome! What rear gears do you have? and if you had to do it over again would you run something different or keep them the same? I live in town and will really only travel long distances on vacation, etc...
 
Last edited:
31709739098_23b3b561e8_k.jpg


Fabricated an air box to keep heat out of the cold air intake from 19 ga steel.
45582048341_3175624c90_k.jpg


I plan to paint the intake tube orange and add the Coyote Duster logo I have ordered to the top as an homage to the ol' days...
45584280941_5fa0f6008e.jpg
 
Last edited:
So moving on, Nathan calls and says the Buick is done can I have the car at his place the next day. Fast forward to:
View attachment 672464

and 24 hours later, the 2009 5.7 Hemi with 50k miles has been placed back on its rightful perches atop its throne of a k-member! Everything had already been mocked up and working once, so now its all just final assembly. I snapped some photos of clearances and random things for people to check out that I hope may help others in the future!

Low mount alternator clearance, mainly notice the dimple we added to the shock tower to make sure it flowed around the alternator.
View attachment 672465

The low mount AC compressor on the driver side fits nicely after K-member perches were cut off and moved backwards.
View attachment 672466

Used sticks of the copper allow tubing from O'reillys for trans cooler lines with compression fittings from Bouchillons to attach them to the trans. The cooler is built into my Champion swap radiator.
View attachment 672467

Used a universal condenser that nearly perfectly covers the opening to the radiator. All the AC Cold hose ran and mounted. I just used black POR15 on the outside of the core support to hide it when the grill and bumper is on.
View attachment 672468

The relays for the trinary and dual fans are mounted on elevator bolts under the front nose piece. It controls fan speed (high/low) for both fans in combination with engine temp and AC pressure.
View attachment 672469
View attachment 672470

Ran the AC cold hose through grommets in the core support and up inside the inner fender before coming out by the blower motor.
View attachment 672471

Another pic of the modified trans mount. basically plate steel with a hole drilled for a standard GM trans mount. (Bolts up really nicely to the 545RFE)
View attachment 672472

View attachment 672474

View attachment 672475

And finally the intake put back on and it runs!
View attachment 672476

Thanks for the pics. Lookin Good Bro! Things are coming together nicely. I see you are using the 5.7 PS pump with the 73 steering gear. Not to alarm you but I have heard the late model pumps can blow the seals in the vintage steering gear. Not sure if there is any truth to it or if there is a way to reduce the pressure if needed. I upgraded to the Borgeson gear so I wouldn't have to worry about the pressure issue. Plus the Borgie is smaller and lighter with a better ratio. It added about a grand to my build but IMO it was worth it.
 
Wow... that's awesome! What rear gears do you have? and if you had to do it over again would you run something different or keep them the same? I live in town and will really only travel long distances on vacation, etc...
I kept the 3.23 sure grip in my car for a couple reasons. First, the whole purpose of my build was economy and being able to run the junk gas we have these days. Second was the knowledge that the first two gears in the 5R45RFE are lower than first gear in the 727 so really don't need lower gears to get off the line. If you plan on racing yours, you may want to drop down to 3:55 with sticky tires but I wouldn't go any lower since my car will spin all the way into second gear with the road gears.
 
Thanks for the pics. Lookin Good Bro! Things are coming together nicely. I see you are using the 5.7 PS pump with the 73 steering gear. Not to alarm you but I have heard the late model pumps can blow the seals in the vintage steering gear. Not sure if there is any truth to it or if there is a way to reduce the pressure if needed. I upgraded to the Borgeson gear so I wouldn't have to worry about the pressure issue. Plus the Borgie is smaller and lighter with a better ratio. It added about a grand to my build but IMO it was worth it.

I kept the 3.23 sure grip in my car for a couple reasons. First, the whole purpose of my build was economy and being able to run the junk gas we have these days. Second was the knowledge that the first two gears in the 5R45RFE are lower than first gear in the 727 so really don't need lower gears to get off the line. If you plan on racing yours, you may want to drop down to 3:55 with sticky tires but I wouldn't go any lower since my car will spin all the way into second gear with the road gears.

I had heard that as well and did a bunch of reading, a lot of guys have had success running it just like it is. So I'm going to try it. The fast ratio I'm sure would be awesome but this project has greatly eclipsed my budget already! lol I wish I could find out what the ps pump is that Bouchillion sells for the 6.1 with the resevoir on it... I thought it off and SRT jeep cherokee but cant find a picture to verify... I certainly am not paying $350 for one! lol

Thanks, thats what I needed to know! The 3.55 were as big as I was thinking because I do like the idea of getting good economy. The 4th and 5th gears would help though!
 
I had heard that as well and did a bunch of reading, a lot of guys have had success running it just like it is. So I'm going to try it. The fast ratio I'm sure would be awesome but this project has greatly eclipsed my budget already! lol I wish I could find out what the ps pump is that Bouchillion sells for the 6.1 with the resevoir on it... I thought it off and SRT jeep cherokee but cant find a picture to verify... I certainly am not paying $350 for one! lol

Thanks, thats what I needed to know! The 3.55 were as big as I was thinking because I do like the idea of getting good economy. The 4th and 5th gears would help though!
Yup. They do. My car runs 1700 rpm at 70. 3.55 gear will only put up to around 2000
 
Auto Transport Service
Back
Top