Replacement exhaust manifolds
 

Hi to all. This will be my first post, but I’ve been reading on here for a long time.

I have a 330 454/ Bravo 1, and have started my winter project tear down. I lost two piston crowns to detonation (having the advance cranked up too much). Currently the block is at the machine shop, and is .060 over. The build consists of a set of 049 casting heads, large oval port Edelbrock intake and 750 carb, and the boat has Corsa captain’s calls. This is a 92 model Gen V block.

I’ve been thinking of running the Crane cam 132561, and getting a set of Comp roller rockers.

My question is- should I be on the hunt for a better flowing set of exhaust manifolds and risers? It currently has the factory 4” risers and manifolds. The risers hold onto the control module (port side) and the shifter linkage bracket (starboard side). If I have to fab up a set of brackets to hold onto those, I can do it. My concern is the restrictive exhaust flow, and the fact that the manifolds have been subjected to 28 years of brackish water.

GLM has a set of exhaust manifolds that are supposed to flow better than stock, and the price is manageable. Is anybody running those and had better performance with them? Also, it seems I’ve read that some folks replace their exhaust with 8.1 manifolds. Is this a viable option?

You can spend quite a bit of money on Stainless Marine manifolds, and others of the like...I’m just curious as to whether you think they’re needed or not. I know this is a mild build compared to most of what ya’ll are running in your boats.

Always nice to lighten up your exhaust however you have any noticeable gains. I had very similar build years ago and experimented with stock vs gils etc and saw no difference other than better sound. You should have a nice reliable package with noticeable overall gains.