I am cleaning up the motors on my new to me boat and I want to replace the crusty original exhaust manifolds. Got them off, no evidence of internal leaks.

Anybody have experience with the GLM stuff? Looks to be fairly inexpensive on eBay, has a 3 year warranty. The motors are Gen V 454's if that makes any difference.

I got them as last minute stock replacements because of the price. IMO, not to bad! They also claim a better exhaust flow because they are cast with about 50%,or so, individual runners . (As opposed to merc's.) I ended up selling them on Ebay for 50 short of what I bought them for.

Just put a set on. Real thick powder coating, I guess to hide the poor casting. LOL. Bolted right up, no problems, no leaks. GLM Gaskets are nice, came with the kit. They do stink for the first 3 hours. Bought mine at amarket marine, they are out of La, and just a two day ship to north Al. I would by them again. I changed mine in conjuction of replacing my old worn out mirage with a mirage plus and picked up 4 mph--mostly due to the prop. They do sound better.


LC

buyer beware- GLM = China Crap

Some might have gotten lucky with the GLM manifolds but I have seen some unbeliveable crap come from glm...I would never take a risk with them. There gaskets on the other hand are excellent...Go figure

I'm curious what everybody else is using? I had Aqua Power manifolds on my 311; no problems what so ever but they are out of business. I even have one in the box, brand new, that I bought as a spare if anybody needs one or has three they want to sell.

I think there's only a handfull of manufacturers, so far I've found Barr, Osco, GLC ... might be others. Does Sierra make their own or do they just resell somebody elses?

I bought some new Hardin SS from Cp Performance (nothing more than rebadged GLMs they even say GLM right on them)
one leaked internally after a week worth of use and took out my freshly rebuilt engine,, they sent me a new manifold but wouldnt compensate me for the damege they caused.

You can find a good used set of Powerflows or Gils for the same money on ebay. Better quality and fit. IMO

I have had good luck with OSCO and BARR. Both are made in america. Sierra's are osco manifolds with a sierra sticker on the box.