307 to 350?
 

Have a 1981 olds cutlass with a 307? (How do you tell the difference between a 307 and a 305?). Also have a 1980 gmc with a rebuilt 350 in it. I was wondering how much work is going to take to make the swap.
Thanks: Justin

Well a 307 has the oil fill tube up front and a 305 doesn't.
Swapping a chevy in place of an olds isn't all that straight forward. The harnesses are different so that would mean either butchering up the one you have to "make it work" or finding a Monte with a 305 to steal the harness out of (and hope it hasn't been all cut up already). And then there's the frame pads that need to be sourced and changed. And the transmission and driveshaft that need to be addressed.
If you have a 307 you're better off finding an Olds 350 because it's a bolt in....no fuss, no muss. No wiring to deal with (plug and play), no trans to worry about (and that means no worries about the driveshaft) and you can use the 307 engine mounts.

Basically with all the money you'd spend on swapping to a chevy just because you happen to have one lying around, you could source an Olds 350, build it, and not hack up the car in the process.