New to the forum and to A-bodies - advice on a build direction

the rally dash is its own beast. the frame itself is different from the standard dash frame (and the wiring). @72bluNblu modded the dash in his duster, so have a look at his build thread for the info there-- and inspiration! it's a great build.

rally clusters show up here frequently, or you can buy new or "versions" of it from classic dash, thunder road, classic industries. i *think* dakota digital was working on or has a johnny hot **** new complete unit, but i can't find the link anywhere.

Even Blu says get a Ralley frame to go with the IP. That's what I've done, but nowhere near ready to make the swap.

Here is his thread:

He get's into the Ralley swap really quick in the thread, post #18 is the start.

The whole thread would be worth reviewing. Best I know, he was one of the first to use 18" wheels on an A-Body and an invaluable source for that and torsion bar upgrades. He even converted his Duster to a Demon.

Appreciate all the comments! I may just take a 3d scan of the dash I have and then model something custom and mill it out. Might be less work than the Ralley dash haha.

Love the front splitter on that Demon above!
I only know of one situation where the tunnel was claimed to not have to be cut, and he moved the motor forward. So I would say yes, the tunnel will need to be cut.

Something to know about the torsion bar suspension is that there is a crossmember over the top of the transmission that supports the weight of the car much like the shock towers in a Mustang. And it is fairly tight and almost always needs to be cut to fit a late model OD trans. If you keep the torsion bars and remove the center of that crossmember it really needs to be built back in somehow. There are those that feel that the bolt in transmission support is enough, but I like the idea of the car being able to support itself without having that support bolted in. This is also why many go to a coil over conversion (COC), it removes the stresses that crossmember sees and frees up room that the torsion bars take up, but it adds stresses to the chassis that it wasn't designed for usually by putting the weight of the car into the inner fender that was only supposed to resist the shock forces. Most (all?) COC kits take this into consideration, but some argue it doesn't fix it all. But that's the builder/owner to decide.

I think a 4L60 needs a cope at the front of the torsion bar crossmember but the tunnel itself doesn't need to be cut. Same with a 200R4, maybe? The A500/42RH/42RE can be bolted in without modifying the tunnel, but the crossmember has to be removed over the trans and a thick (1/2"?) plate welded to the floor and ends of the crossmember. For an automatic OD, I can't think of any other options beyond the 5 speed the earlier LX/LC's came with and it is much more complex to swap, needs the same floor mods and isn't as good a trans as the 8HP70/90.

One note; it is my opinion that the single biggest mod anyone can do to a car to make it more modern and enjoyable to drive is an overdrive transmission of some type.

Okay great info. Perhaps a 4l60 is in order to get a speed of OD without having to go too invasive. If this were a keeper I'd go full into it, but not sure there is a return on investment from a 4speed OD to an 8speed in the open market. If I was building for someone already in mind, sure, but to the masses, maybe not?

And I agree that an OD does make a HUGE difference. Feeling those RPMs drop when you're used to 3,000 RPM+ on the highway is such a good feeling. I remember doing my first OD swap and just how much more relaxed I was on long drives with it.
Thanks for inviting me to the party @DionR !

I'm obviously a fan of the pro touring style build because, you know, go fast and turn... I'm also a fan of understated, tasteful modifications. I do think some builds people call pro touring are over the top and look like hot wheel car builds. Those are just dumb and have zero resale value.
As with any project, the budget ultimately determines the path. Since you aren't super familiar with the Mopar A-body platform, my suggestion is to keep it simple, especially if you plan to sell the car.
My recipe for resale would be as follows:
  • Keep the exterior as close to stock as possible. Don't put any silly wings or hood scoops on it unless they were period correct for that car.
  • For the interior keep it simple. You don't need some out of place console and 20 gauges with 3 double din stereos with navigation and all that other crap. The key is making it comfortable, but also keeping the nostalgic look.
  • Yes modern hemis are kind of common, but that's what buyers want right now. Slap a modern hemi with an 8 speed auto with the stock computer and send it down the road. Sublime Technologies (Formerly DIY Hemi) can make a factory engine/trans harness plug and play. Yes the 8 speed will require some tunnel mods, but it seems your shop is capable. I recently saw someone use a tunnel from the modern Challenger as a replacement for the old narrow tunnel. I thought it was a fantastic idea since the modern tunnel was already shaped to fit the trans. It saved a ton of fabrication time.
  • Suspension- Again, since you aren't intimately familiar with the A-body, I'd go with a @HemiDenny HDK K-Member. It will make installing a G3 hemi a breeze. The cool thing about Denny's kit is, you don't have to run a huge brake that requires an 18" wheel. You can just use a smaller 12" brake and run 15" wheels. If you tried to use the factory K and aren't familiar with all the nuances, you will get pissed and abandon the project. Also, for reasons beyond my understanding, most people automatically view coil overs as being superior to torsion bars. That automatically intrigues a buyer. For rear suspension, Bergman Autocraft can sell you some leaf springs that will work great and get the car sitting right. Or there are some 4 bar setups out there- I believe QA1 makes one.
If you decide to go the 5.7 G3 Hemi route, get an 09 and up engine. They switched to VVT in 09 and the cylinder heads got much better.

I'm happy to answer any questions you have!