I was wondering if anyone out there has installed an aftermarket set of exhaust manifolds and flame arrestors on 350 mag mpi's and if so what kind did you use ? I eventually want to supercharge the moters and thought aftermaket exhaust manifolds would be a good place to get started. The boat is a 05 292 fastech.

You can make the changes for the future , but right now you more than likely won't see any difference with the F/A and MAYBE 1 mph with the exhaust but that's unlikely too.
I had a 272 with t/330 big blocks and did get 1 mph with Imco Powerflows. K&N filters...zippo

yea... but sure looks better .

Yeah but I kept the exhaust and put new engines in between