2 5cyl turbo motors around 300hp each auto to aftermarket computers with all limiters removed . two hks ebc. took a front crossmember and fitted in the back.took just over a year to build.the fastes car i ever drove.
During the gas shortage GM actually designed a replacement for the corvette. It was a twin engine Beretta. Road and Track mentions it every couple of years when they do the "expose : GM TEST VEHICLE (insert buzzword/phrase)YOU MUST SEE TO BELIEVE)
The engineers said it was insanely fast, and I think they were only using 2 4-cylinder engines.