1968 Roadrunner: 6.1L hemi, 6 speed, & IFS/IRS

[andrewb70]

Man....this is a labor of love...and you have mad skills!

Andrew

[octane speed shop]

Wow a real 68 post car. By the way what are you going to do about the trans crossmember for you six speed, aren't those late model six speeds beefy right about part of your car?

[70B5Cuda]

Wow a real 68 post car. By the way what are you going to do about the trans crossmember for you six speed, aren't those late model six speeds beefy right about part of your car?

The 6 speed is quite large. The center of the torsion bar crossmember had to be cut out and a new crossmember will be constructed. Pictures coming soon!

[72BBSwinger]

This ^^^^

[68Cuda440]

This ^^^^

[minendrews68]

Nice! This is going to be a great looking car. Keep it up, and yes, we all like pictures...

[70B5Cuda]

I took the dash frame to a local powdercoater, who blasted and powder coated it in a satin black. The only blasting cabinet he had big enough to blast this dash used coal slag, which is quite aggressive so I was worried it would warp the metal. I asked him to turn the pressure way down; he said he used 40 psi (instead of his usual 100 psi) and it turned out great! I am really happy with the texture and finish. Plus I got rid of the UGLY marroon.

I don't have a good picture of the dash frame beforehand, but the metal around the VIN plate will give you an idea of what it looked like. This car had been sitting in a field in western kansas without a windshield for more then 1o years so all the paint had been baked off the top of the dash frame







After getting the dash frame pwdercoated and buying a new M&H dash harness, I started thinking, which is never good for my wallet. I realized I didn't want to work with the taxi dash gauges so i began looking for a 1968 rallye dash frame, which I bought off facebook. After considering dash options, I decided on a Dakota Digital unit for several reasons. First, I really like the look. Secondly, the TR6060 doesn't have a speedo output so Dakota has a GPS based speedometer box which is plug and play with the Charger VHX gauges.

[70B5Cuda]

The driver's side quarter had a bid dent on the character line. Picture before...

[70B5Cuda]

I've got a 70 Cuda restomod that has snowballed out of control. Im currently 8 years into a 3 year build....Im sure many of you can sympathize. So....my original intent for this Roadrunner was for it to be simple. I had decided on just doing some sheetmetal repair and as far as drivetrain, I was going use a Gen 3 6.1L hemi, 23 spline 833 4 speed manual trans, and an 8 3/4" rearend. I didn't want this project to spiral out of control either so I was dead set against change. I just wanted to keep it simple to speed up the build, save money, and not have to cut the floor pans. I had a 4 speed completely rebuilt/ painted and I bought all the parts to convert from a 727 auto to a 4 speed manual.........and then one day I added up the costs of a installing an 833 (see list below) and I realized how much just a 4 speed costs.....I decided to install a TR6060 6 speed instead of an 23 spline 833. The 833 4 speed would have been easier and faster, but...

1. I had a 50K mile TR6060 sitting in the shop....with everything needed to complete the swap. I had parted out a 2009 Challenger SRT8 so I had the stock twin disc clutch, pressure plate, flywheel, hydraulic throwout, hydraulic line/reservoir, clutch pedals, etc....just waiting to be used. And it was originally paired to a 6.1 so it was easy to assemble.
2. I started adding up the value of all the parts for the 4 speed swap: rebuilt 833, Lakewood SFI Bell housing, new Mcleod clutch/pressure plate, Mopar Flywheel, hydraulic throwout bearing setup, z bar, fork, actuator rods, boot/seals, fork pivot, pedal assembly, etc and I thought... "Why am I spending this much for a 4 speed?!?!?!?!?" I'll could sell it all to pay for the tunnel and crossmember fabrication work."
3. I didn't want to cut the tunnel and floor for the 6 speed but in reality I want to drive this car to work 1 or 2 days a week (70 mile roundtrip) so why go to the trouble of a Gen 3 hemi with a 4 speed?!?!

At first I really didn't want to modify the floor pans since they were pretty solid, but I finally came to my senses. I'm really excited about the subframe connectors, which are made of 2"x4" steel rectangular tubing that channel through the floor pans. Should really help to eliminate flex and improve rigidity.

[70B5Cuda]

[70B5Cuda]

View from below which shows how the 2x4" ties into the rear frame rails

[Godbolt]

I really like where this is going. If you are building it to keep, may as well do it right. Great progress.

[70B5Cuda]

I really like where this is going. If you are building it to keep, may as well do it right. Great progress.

Thank you! My thoughts exactly!

[brawls43]

Totally agree with your logic on the 6 speed vs 4 speed. Same reason I ended up doing a 5 speed in my truck. Daily driving without an overdrive is rough.

[Dave Pratt]

How did I miss this! I had a 70 RR before I bought my 69 Camaro.Too tired of paying double for parts as compared to my friends and their Chevys but thats anothe rstory.I still have a thing for Mopars though and I really like that 70 SuperBee you have in the back ground.I think it's a Bee but one of my favorite rides.Really like the work you did on the subframe connectors...keep er' goin!

[Zoomin]

How did I miss this! I had a 70 RR before I bought my 69 Camaro.Too tired of paying double for parts as compared to my friends and their Chevys but thats anothe rstory.I still have a thing for Mopars though and I really like that 70 SuperBee you have in the back ground.I think it's a Bee but one of my favorite rides.Really like the work you did on the subframe connectors...keep er' goin!

i bought a 66 Fury without doing research on the costs. It's languishing while I figure out a plan.

It sure is nice to have access to metal skills like that, and a great idea to fix the rear tubs while you had a chance.

Has your 383 found a home yet?

[70B5Cuda]

i bought a 66 Fury without doing research on the costs. It's languishing while I figure out a plan.

It sure is nice to have access to metal skills like that, and a great idea to fix the rear tubs while you had a chance.

Has your 383 found a home yet?

Thanks for the encouragement. I am indeed fortunate to have found such a good fabricator. He has done all the fabrication on my 70 Cuda as well. https://www.pro-touring.com/threads/...uda?highlight=
I haven't figured out what to do with the 383 yet. It would surely need rebuilt but I would be open to selling it.

[70B5Cuda]

This picture is looking to the rear of the car and shows the driver's side subframe connector which channels through the torsion bar crossmember and ties into the forward frame rail:



Same rail just viewed from the side:



Passenger side subframe connector tying into the front subframe rail:

[70B5Cuda]

Originally I was going to make the original K-frame/torsion bar setup work but I changed my mind and decided to go with Reilly Motorsports for the front suspension. The RMS Alterktion setup showed up this last week. Woohoo!





The trunk floor pan was really quite solid but there were a couple small holes along the trailing edge that Matt patched:

[70B5Cuda]

I'm really excited about this next development. I had a few IRS K members laying around from SRT8's I had parted out so Matt convinced me to go IRS in the Roadrunner. I love the way my 2010 Challenger SRT8 handles/drives so that helped greatly in the decision. The K frame will need to be shortened 2 inches in the middle and the original mounting pads will need to be cut off so the IRS frame can slide between the Roadrunners rear frame railst. This is the IRS K frame before modification:



First thing, the K frame was reinforced/boxed in a few areas: