I have been all over the map on this one I was looking at 2 options for the motor + trans in my 68 cutlass convertible:

1. mild 455 with aluminum intake, edelbrock carb, mild cam, dual exhaust a th400 with a mild stall and a shift kit.

2. 350 #5 heads, aluminum intake, edelbrock carb, mild cam, dual exhaust
a th350 with mild stall converter and a shift kit.

The car is just a cruiser, but I'd like to have decent power and not burn too much gas.

I'm leaning toward doing the 350 right now, as I just checked the numbers on the block and it is a 68' numbers matching correct motor for this car.

Opinions and advice are welcomed, thanks

 

When I decided it was time to start updating my 70, I was faced with the excact same dilemma. I stayed with the 350 put an Edelbrock intake, some mild head work, a Comp Cams Extreme Energy cam (somewhere around 496 lift, don't have the specs here and I am away from home), with a 750 cfm Q Jet, and of course headers. This combo is a bit above stock, should give me a nice mild lope at idlen but still have decent cruising manners. If I were going to at any time race it, no brainer, 455.