I have a 355 with a stock 350 cam and I'm assuming stock pre-86 heads since they're perimiter bolt and I'd like to upgrade it a little bit. It already has shorty headers on it but honestly in terms of power thats about it. Someone on craigslist is offering a 97 Vortec block really cheap but I want to be sure its a Vortec. Does anyone have a list of Vortec casting numbers? And when I do get some new heads I know that the SBC intake manifolds won't match up but are the exhaust ports the same? What kind of cam would be good for a mild setup like this? I get 26mpg highway with what I have now and I'd love to stay around that mark, and I'm not sure if a cam would hurt those numbers or not. I don't think that better flowing heads would for obvious reasons. Any help you guys can give me would be appreciated!

 

Moving this to Tech/General Engine because you aren't really asking about an engine swap.

The 350 Vortec head casting #'s are 906 and 062. The exhaust ports are the same as earlier SBC's.

What induction are you running on this engine? That will dictate to some extent what cam you should consider. Plan on new valve springs at a minimum, though.