I have a 96 velocity 260 looking for exhaust to run on my boat. engine now is a 454 with a zz502 cam, with factory heavy ass manifolds and risers. currently im building a engine (502) merlin heads, custom boat grind, and the performer rpm and carb I have now till I can piece together a FI set up. I was told there is all sorts of exhaust that came on mercruiser engines that I could use for the little bit of power that im going to be making. one suggestion is the 496 manifolds and risers. I truly have not a clue on what to get. any help would be appreciated. also budget is a big factor in this. I don't have 2k to blow on exhaust.,....

2k is a low price for good performance exhaust. Most are more. Save a little extra and look for stainless marine.

I understand that,.just figured for the low performance I need I could get away will some factory high performance stuff till I win the lotto.

The mercruiser/gil manifold setup like the hp's had can usually be had pretty reasonably and give you the performance youre after.

Honestly the 496 manifolds would flow plenty, it becomes more a question of the final cam decision and reversion. Granted there are many variables beyond the cam that control that tendency. The main drawback of the 496 manifolds are the relatively short risers. You should consult a guy like Bob Madera to grind you a cam and evaluate this whole "system". Too many times I think we get focused on one aspect of a very complex animal that Performace marine engines happen to be.

If you decide to go with 496 exhaust I have a nice set $500.00 + shipping. Randy

I PMed you thanks..

Heres an article on swapping the stock exhaust on a 496HO, to Dana Marine and Lightning headers.

Looks like the Dana setup picked up 23HP over the 496 exhaust, and the lightning headers picked up 20hp over the stock 496 exhaust. I'd like to see a comparison on a 500or 600HP engine at 5500RPM.

http://www.fullthrottlemarine.com/49...%20Article.htm

Get those Merlin heads checked before bolting them on....You never know what lack of quality you're getting from them. I know too many people burned by them