Originally Posted by El C
Here?s the problem.
One choise for 1972 El Camino was 307.
Chevy discontinued 307 at -73 (am I right?), but Buick and Oldsmobile (mayby also Pontiac) uset 307?s much later.
These are not the same engine, are they?
My El C has a THM200c transmission with Chevy bolt pattern (now with Chevy 250 inline 6 engine) and when I see a 307 it?s with the BOP bolt pattern, so it doesn?t fit.
If they are not the same engine, should I go with later Chevy 305, that fits?
Also, which is better for a daily driver?
BOP 307s are not the same as Chevy 307s but they can be adapted with commercially available adapters from the U.S.
A Chevy 305 is also a bolt in against your existing mounts, radiator, and Chevy trans.
A 350 would be nice and TH200s can be built to live with it again you need parts or a tranny probably from the U.S.
Given you already have a 250 inline 6; another interesting swap choice if you can find one is the 292 Chevy 6, it's found in trucks. The block is a bit taller than the 250 so you'd need to check that the hood closes, or put a bubble in it if it doesn't. The GM inlines are well supported with aftermarket hot rod parts and building a 292 that will embarrass a moderate small block V8, isn't too hard to accomplish and a lot of fun to do. The 292 passenger side mount is located differently, you'll have to take it from the truck or cut an adapter from some steel plate, no biggie, hand tool job if you don't have a welder or mill.