I have in my posession a bored 350 block ready and machined for the 383 parts I have, and just sitting in me fathers newly purchased '88 Iroc is a 454 and TH400 that has a 1000 miles driven on the setup. He has agreed that if I want the big block setup then he wants the 383 stuff I have. I've always wanted a 383 but with a big block at my finger tips I'm at a cross roads. Just asking for some persuasion...

 

What do you intend to do with the car? To me that would really be the deciding factor between small block or big block. If the car is a drag race or cruiser car, the big block would be a lot of fun. If it's a frequently driven car, or a car that you expect to be able to go around a corner, I'd go with the small block.

Of course, all of this is assuming that it's a nicely built big block vs. a nicely built 383 that we're talking about here too. If it's a peanut port 454 with a stock cam, I'd never waste my time and money doing the swap.

 

Agreed. The big block is 4.290 bore (461 displacement). We don't know the cam size yet. But it definitely isn't stock but not big either. The PO didn't know either. Never dealt with big blocks but my father has. The end goal is not decided, it will eventually be a weekend car only, until then I drive it faithfully daily. So until I get something else to drive daily this is it with these options.