Mercruiser Exhaust Manifold vs aftermarket

"Gentlemen: I plan to replace

"Gentlemen: I plan to replace the port exhaust manifold on my RWC 4.3L mercruiser. I already replaced the starboard man. two years ago w/a merc. brand manifold. My question concerns using a new GLM brand for 1/2 the cost which has a different internal design that separates exhaust pulses. Will it make a difference in perfomance by using one merc. and one GLM? Or, should I buy a good used merc. manifold for the price of a new GLM? What type and strength acid do I use to clean out the used man.? Your opinions are valued.
Guy"

"I would replace them both wit

"I would replace them both with good used Mercs, or new GLM's, I think the GLM's are a few pounds lighter that the Mercs, so there is a benefit there also. You may not notice any difference in operation with mixed manifolds, but it would nag at me, as in my mind I would know they were different. Just me I guess.
Rod"

The GLM's seem to be good

The GLM's seem to be good quality for the money. They also offer an aluminum model that will shave alot of weight but if you hit salt water stick with cast iron.

Performance increase will be very minimal if anything at all as the stock manifolds are flowing plenty for a stock 4.3L. I see no problems with replacing one manifold as long as the other is in useable shape and not leaking.

"Thanks guys. Since the starb

"Thanks guys. Since the starboard is a 2 yr old genuine Merc., I'll get a good used one. Guy"