GLM Cast Iron Manifolds
 

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.