Saw an article in Super Chevy (I think...) where a Corvair and 1980's G-body (Monte Carlo/Grand National/Cutlass/Grand Prix) had the same wheel base and similar track width as a Corvair, and the Corvair body was put on a G-body frame and floor. LS1 / T56 or 4L60E is an EASY swap as the Monte Carlo folks are selling conversion kits.
I thought about this myself for my project after the 1969 Camaro but found an awesome deal on another project car (Need an old car as a foundation out here in California to stay away from the smog nazi's, and I've worked on Corvairs in the past).
Wouldn't take much to get a dead G-body for next to nothing, box and stiffen up the frame, get a DSE suspension kit and you would have quite a foundation to start. Tons of other g-body related parts too, 9-inch rear ends, big brake kits. Need to look at a few things that need to be thought out ahead of time, like cooling the engine, as the Corvair has no grille, but those kinds of things have been worked out before.
Ton of work, on a proven chassis, but easy to do if you are a handy welder and fabricator, and have the time and ambition. Here's an posting on a LS1 conversion. Found it quick, and I've found a few other tech articls on other pages too, I just don't have time to dig them up.
http://www.ls1tech.com/forums/conver...1-corvair.html
Hmmmm.... Can I post an article from another site and not get it deleted.... Guess I'll find out.....