Well that probably would depend a lot on where you are. Alaska?
Florida? Southern Spain?

The 502 uses a taller block that the conventional chevy big block line
so you will also need intake. I believe the heads are basically the
same but you might have to deal with the exhaust manifolds being
slightly further apart than your existing installation. Probably not
something that can't be handled fairly easily. The rest of the stuff
should bolt on. Make sure you do have a little clearance between your
two 454s because the 502s will take up just a tad more width.

Big gus wrote:
Hi

I need to rebuild, or replace the 454's in my boat

is there any really good shops out there to get a set of rebuilds
from?

Next question
repower with 502's

anyone ever done this?

and where is a good place to buy a pair of marine 502 long blocks?