I just wanted to say I got got a SS Plog and it is super nice quality, very nice welds. It'* a little close to the a/c compressor for my liking, but it does not hit. They might have been better to start about 1.5" under the #1 cyl and neck up to 2" where the #3 tube comes in, that would have given more a/c comp clearance, but hey, what more can you aks for for 175-bucks? It'* very nice. It has turned a cool shade of blue-ish gunmetal after about a day of driving. It installed in less than 30 minutes.
I woudl recommend one to anyone over the stock manifold. I was skewing the rear 10% (adding fuel) to even out the engine with the stock manifold. Now I am down to only 5% and only on #2 and #4 (I have a rear header for the turbo, so it'* different than the stock L67 skewing requirements) In other words, it works nearly as good as my custom rear header.
One thing I noticed, I get a weird "waa-waa" exh harmonic from 2500-3000rpm. It started after I installed the plog. It might have been due to the 10% rear skew, which is much less now. I will listen close tonight on the way home to see if it went away.
Plog = Good money spent!
1988 Grand Am SE 2.0 Turbo
1996 Bonneville SSEi Twin-Charged