71' Gran Coup Gen III

[CudaA39]

So I figured instead of putting my photos in my intro thread I would just start a build thread and begin documenting my progress.  I am also taking video with a GoPro Hero7 with plans to create a build on YouTube to hopefully act as a resource to any average car guy like myself.  I'm not the first to do this, and I certainly hope I'm not the last.  I'm also not an expert in anything automotive so go easy haha.

As mentioned before, this car started its life as a lime green 71' Grand Coup with PW, PS, AC, 318 4bbl with 3.23 rear.  It had all of the Gran Coup standard options.  We never had the original engine and trans, and even if I did, it wouldn't have been used.  It was purchased in 95/96 and has pretty much been a paper weight ever since.

My goals with this car is to utilize a somewhat stock Gen3, match it to a rollerized 727, add a Dana 60, and run 11.50s on a 9" tire.  I sold my Coronet racecar because it wasn't street legal, so this will be the best of both worlds.

When I began digging this car out from the 20 year hibernation, I was pleased to see my dad had saved so much of the original car.  I began to unbox and separate everything by category, with a goal of engine in/on wheels/moveable by 2020.  The car was a bare shell filled with body panels sitting on two box beam steel frames.  Not a single part is bolted on.

The engine is a 6.4 BGE from a 2017 Ram5500 that was lost in a fire.  It had 16k miles on it, a truck front cover, and even had a PTO (for sale if you need one).  I won't say what I paid, but it was an absolute steal, so the deals are out there.  It cost less than my last rebuild on my 451.

In order to meet my goals for the year, I assembled the rear suspension and original 8.75 just to get it off the fixture   I went to Modern Muscle in Florida and order a Steffs oil pan and pickup.  The quality is absolutely first class and I'm so glad I didn't go with a milodon pan alternative.  After delay after delay with Schumacher for engine mounts, I got a sent of TTI conversion mounts from Mancini and decided to get to work on an engine cradle.  With a 45* oil filter adapter, and using a homemade lift fixture, the engine lowered onto the k frame without too much effort.

With the new wooden dolly holding the drive train, I lifted the front end up and slid the engine under for the first time.  As Ace Ventura would say....like a glovvvve.

For an intake, Prefix recently had a production run of their single plane intakes, so I got one drilled for fuel injection as I plan on doing common rail port injection.  This setup should be fairly well hidden under the oval hemi air cleaner I'm hoping will fit under the non shaker hood.  With limited production runs and the need to look at hood clearances, the intake had to come a bit early.

I'm 31, so for 24 years this car sat unused, as a staple to our garage.  I can't begin to convey the feeling I had seeing it sit on wheels once again.  I lost my dad in 2011 right after graduation, so this build will be dedicated to him.

[CudaA39]

Due to the nature in which I plan to use this car, I've decided to forego the 4 wheel drums for a set of Wilwood 4 piston vented/slotted fronts, and Wilwoods on the eventual Dana 60.  I originally wanted to utilize their 6 piston 12" setup, but apparently the only OE wheel they won't clear is the Rallye, which I have.  I don't anticipate running them often as I have a set of Welds line up, but I didn't want to chance it.

The Wilwood kit is pretty straight forward and bolted up flawlessly to the drum front spindles.

Front suspension will utlize the stock torsion bars, as I just couldn't justify the money to go coilovers conversion.  I don't want to sway too far away from 1971.  Single adjustable QA1s will give me the ability to drive to the track, adjust settings, race, and then drive home.

Upper control arms are PST tubulars with the heim joints.  I had QA1s on my Coronet, which were a huge step up from the OE bushings, and these seem to be a huge step up from those.  I want this car to leave like a hemi car should, and because I'm not mini tubbing, it'll take some weight transfer.

Steering components not yet installed are all new Moog parts, and I decided to go with a new Borgenson steering unit due to weight, size, and function.  I just got it in from Jegs this week, so once I get it installed I'll be order the TTI headers and working on the front accessories.  I plan to retain the AC.

[anlauto]

Cool project 

[CudaMoparRay]

Looking forward to your progress on this thread

[Brads70]

Looking great! 

[BFM_Cuda]

Great project! I am building a similar challenger..

[303 Mopar]

You're going to love the Gen III. Feel free to use my thread if it helps.

https://forum.e-bodies.org/modern-hemi-swaps/26/392-hemi-swap/67/

[CudaA39]

You're going to love the Gen III. Feel free to use my thread if it helps.

https://forum.e-bodies.org/modern-hemi-swaps/26/392-hemi-swap/67/

I actually have referenced that thread a few times, great resource!

[moparcar]

Looking forward to your build. That Prefix intake is nice. Have you mocked it up to see if it will fit with the throttle body under a stock hood? I keep getting mixed comments as to whether it will fit. I'm building a Challenger with a 3G and would love to use a TA hood with a factory sealed air cleaner assembly with one of the single 4-barrel bottom pieces.

Wes

[CudaA39]

Looking forward to your build. That Prefix intake is nice. Have you mocked it up to see if it will fit with the throttle body under a stock hood? I keep getting mixed comments as to whether it will fit. I'm building a Challenger with a 3G and would love to use a TA hood with a factory sealed air cleaner assembly with one of the single 4-barrel bottom pieces.

Wes

Wes, it's a super nice intake, with casting quality a step above what you'd expect from Edelbrock.  Dale and I are working on a minor issue right now with the oil fill port, but the port cleanliness is really nice

I'm hoping to get get everything situated to rough fit the front fenders and hood, which will give me an idea of the dual snorkle hood will clear.  Accufab sells a low profile 4150 that is half the height of the Drag Pak tb, so I will keep everyone posted on hood clearances.  Preliminary measurements seem promising for sure.

For what its worth, Dale at prefix said they have customers that are doing this under a stock Hood.  Kent Ritter and I had a good conversation on the same subject, where he said his short Drag Pak intake would work too.  Stay tuned for more pictures

[Shoooter]

Cool project,  will be following this one forsure!

[CudaA39]

So I finally finished the front brakes and 90% of the front suspension (one of the QA1s is going back for a replacement).  The tires were pretty shot and wouldn't hold air so my good friend gave me a set of 205s that would work to move the car around, letting me finally lower the car on all four wheels.

Next project will be the Borgenson steering unit install and trying to figure out if I can use the truck power steering pump that came with the motor.  The clocking is a bit different, so the reservoir won't work.

[ec_co]

on the G3 power steering I've heard they provide too much pressure for either stock or the borgeson unit and blow lines out quickly. not sure what the solution is, I think I remember someone saying they used a GM power steering pump????

[CudaA39]

on the G3 power steering I've heard they provide too much pressure for either stock or the borgeson unit and blow lines out quickly. not sure what the solution is, I think I remember someone saying they used a GM power steering pump????

I've also heard that same thing.  I need to do some research to see how much PSI the pumps produce, vs what Borgenson says they need, as I recall theyre close enough a line restrictor may work.  If all else fails, Bouchillion sells a hemi pump that is choked down 15%, but it's fairly expensive.

[CudaA39]

Got the Borgenson steering unit mounted.  Very happy with the size and weight savings with this unit.  I'm hoping all goes well with the steering column and eventual performance, which will tempt me to put one in my Roadrunner.