Looks like i need to replace the Gil's that I have on my 502's.... was considering going to headers... any considerations I need to look into? and how badly will I get raped on headers?
Seems this isnt like throwing headers on an old 350 SB anymore... Thanks.

it looks like you have a Cig Top Gun, so headers do look really nice in there. But plan on replacing them every 5 years or so as the vibration tends to fatigue the joints and can hydrolock the engine. Your results may vary. Stainless Marine manifolds seem to perform nearly as good as headers and last forever.

I'd have to argue with that rooster man. Standard stainless marine manifolds, have got their azz handed to them quite a bit on most modern marine N/A BBC builds. Mark from MER Performance had a mild 509 on his dyno this spring, that dropped 40hp and 35ft lbs of torque across the powerband by bolting on stainless marines vs his dyno headers. 40hp is a good amount in my book. Epecially when the power gains are throughout, and not just at peak.

Those GIL/Stainless marine/imco/EMI types of exhaust are more like comparing a shorty header to a long tube in the car world.

If I had to buy new exhaust, and didnt want the problems associated with stainless headers, I'd get these

Thunder-N-Lightning Cast Aluminum Exhaust Headers :: Thunder & Lightning Headers :: Exhaust Systems :: Diamond Performance Parts

Loosing 40hp from dry headers, good to know. Wonder how the Eddie Marine did. Reason to ask is mine was at 530 on dyno but have EM but have the +3 on it now
EMI Thunder Exhaust System-BB Chevy +3" Taller Risers Colored Finish

What kind of life span can one expect from the Cyclones? My motors were built in 2009, at that time the Cyclones were new. Now based on what Rooster said I'm slightly paranoid..

why don't people dyno their engines with the exhaust the engines are going to run with? you see virtually every engine dropping 25 to 40 hp from the dyno headers to the marine exhaust.

Lightning headers!!! Got 14 years out of mine in freshwater.

Here you go -

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I second mild thunder. Diamond Performance- thunder n lightning.

I have,

Set up is a little tough, but not bad.

You have to get a dyno shop interested in doing it and you will have to help with $$$$ and time. So, in general, good luck with that.

BT: Water supply for some places can be tough. Those Bravo sea waters pump move massive amts of water. You would be incredibly surprised watching it in person.