Kinda OT: Making a '64 Impala safe and reliable? EFI/OD conversion questions...

You could also do it like my friend did with his 64 Biscayne 2 door post. We pulled the 283 and replaced it with the 290HP crate 350. Of course, it bolterd right in. We put in an HEI, tight but not firewall hack. Edelbrock intake and carb. He drove from Tucson to Colorado Goodguys and back and got 17/18 MPG with the stock Powerglide and the AC on. We are getting a 700R4 ready to swap now, then on to a disc brake conversion. He can do it in stages as time and money permit.

 

BINGO !

 

I agree, I picked up one of those 350 motors for like 1300 brand new from the dealer, I had popped the engine in my 65 impala and was in a real time crunch and needed to get going quickly, It was super easy, the horsepower was a little low but it worked good.