Hello, I recently acquired a 1975 LeMans which had a 250 inline 6-single barrel in it. The motor died a few days ago and now I have to hunt for engines and want a small-block 350 in it to make things easy. I am wondering if I'll need a new transmission( mine's a 3spd auto) or can I bolt it up to a 350?....If I have to change the tranny too, I'm wondering if my driveshaft will be the right length. I've tryed to find this stuff online and I am coming up empty handed. So here I am asking you guys for some insight.

thnx, mike

yes it will work

Yes, it's fine. The best thing you could do to make that conversion to V8 easier is to find a complete Chevelle or Lemans with a 350. That way you would have all the parts necessary such as brackets, exhaust manifolds etc.

thnx guys for the quick response. Would a 305 cid fit also? I am finding alot more of these motors online. Some with transmissions for cheap. Would the whole motor/tranny combo fit the driveshaft length?

305 is identical externally to a 350. There is 3 choices of turbo 350 lengths though. Best to keep your trans.

Close to it I think but then he needs all the mounts, brackets etc.

Got another question. Would an exhaust system from a 1979 Firebird, hook up to the 350 im planning to put in?. Or are they completely different under there?

No, you will need an exhaust system from an A body with a Chevy (Canadian Pontiac!) engine. That would limit you to Lemans with the Chev 350 or else a Chevelle I guess.

I must have been asleep on this thread, just found it now.  Excellent responses Carl !

I have to admit, I was surprised someone as faithful as you had not replied Ray!