I am helping someone do one now and he got a whole rear section from, I beleive, Chassis Engineering. Since it was going to be a drag racer with a narrowed rear and tubs, we simply cut out anything that got in the way. We welded everything in and installed the full cage and welded that to the rear section. The four link suspension was part of the rear section and not an add on to the original frame. So it was pretty easy to do. I suppose, you could do the same and install a four link to the original frame if you wanted to. The only thing is that you would be limited to what size slicks you could use because of the narrow wheel well. you would have to reinforce the whole thing. So I don't think that it would be wise to got this route. You might as well go the whole way even if you don't put a full cage or large wheel tubs in. Either way, it is a lot of work. But in the end, you will appreciate it. We figure that we won't be having any flex problems later. And dialing in the right amount of traction will be alot easier. Our efforts will be better realized to focus on engine and transmission gremlins.
Here's the dilemma,, I'm building a 560-575 HP stroker with a 250 shot of NOS,,,I've got a Dana 36 rear and that won't last squat! Looking at the Dana 44 and better half shafts,,I'm looking at about $1800 plus,,,and still stuck with all those damn U-Joints,,,and can't legally go under 10.00 flat!!!
So I really just want to eliminate the half shafts and be able to run up to 11.5" tires,,,maybe the 10.5 DOT class. I know I'll propably never see those times, but I still don't want to deal with the hassle of half-shafts,,and the lack of strength of the Dana 44 as compared to the Ford 9", Chevy 12 bolt or Dana 60 rear-end, besides anytime you mention the word Corvette, when it comes to gears and parts, vendors automatically get stupid with prices!!! Have you ever compared the price of lockers and gears for a Ford 9" as compared to the Dana 44,,,it's just plain crazy!!!!!!!!!