Has anyone had any experience swapping an LS1 into a thirdgen? I was just wondering about motor mounts, tranny, and the fit in the engine compartment. How about the gauges, will they work?

 

why don't you do a search, or even scrool down this page, read everything you can and then come back with some questions.

 

This month's Chevy High Performance they had featured a guy who blew up his 305 TPI and put the Ls1 T-56 in the young guns section.

With a little research most of your Q's can be awnsered by yourself. Compare the specs of your car to that of a 4th gen. If you are serious pick up manuals for both cars.

There is almost no one you knows those kinds of things off hand.