I am currently underway with a swap in my 1950 Chev Hardtop. I had a 406 chev small block with a 700r4 trans in it. I sold it to a friend (it had 12k miles on engine & trans). I am putting in a LS1 and 4L60E out of a 2002 TransAm. The engine is in and fits great, although we had to pocket the frame in a few places. I have a Mustang II in it and the pan clears it good. I have Sanderson headers on it and they clear good to but I had to move the steering some. My big concern is where to put the electric cooling fan. I may have to move the radiator ahead or I may just try a puller fan in front of the radiator( not the best choice but it may work. All my friends think I am crazy for swapping this but my mistake was driving a friends 2002 Corvette this summer! I fell in love with the LS1. It has great HP and is smooth running. My 406 small block was built pretty wild, shook the windows at the stop light! I drove it for 3 years to car shows and won MSRA Custom of the year last year in Minnesota.