Does anyone have any experience or feedback on the GLM replacement manifolds on a 502 MPI?

If your going to spend $ for the kit, you might as well upgrade to a performance exhaust.

Revolution marine or Eddie Marine is the cheapest and easiest.

I just got rid of my silent choice, and stock cast Iron Manifold and risers. Put on the EMI thunders and the boat runs and sounds great.

The only problem was with my Oil filter housing bracket. I had to modify it, as well as move the drive fluid reservior bracket and reservior and screw it to the transom.

I also ran into some rusted manifold bolts that were a pain in the ass to get off. It was a good thing we pulled the motor. we had to use a torch on 2. and a torch and sledge hammer on the other.

Your gonna need a good die grinder to get all the old gasket material off the block, before putting on the new gasket.

Thank you Lord Stanley. I have done some homework, as far as cost, GLM blows them away for the price. But I am not sure on performance. I know what you mean about the rusted bolts; a size smaller socket, impact driver, a busted knuckle, and a ton swearing was necessary for the side I have already removed.

Well we pretty much have the same set up. So tell you what I did.

EMI thunders with the Stainless Riser
K&N airfilter

New plugs, wires, cap and rotor.

Im running a Bravo 1 22 pitch, unlabbed.

Last year 63.4 gps5000 rpm., full water tank, 3/4 gas, light tackle.

This year I hit the Revlimiter at 5200 and 59mph. However I was light on Gas, no water and no tackle.

Im about to head on a weekend trip to C&D canal. And I'll let you know the performance of a heavy boat with the new exhaust and air filter.

I can tell you that the boat is breathing better right off the bat.
there is going to be a performance increase, but it wont equate to much. 1-2 mph maybe.

Thanks again Lord Stanley, I would love to hear the results. I also just bought the K&N, NGK Plugs, and about to install the new exhaust. I still have the OE Bravo 1 prop. Will be going 4 blade soon.