I am trying to nail down how many stock exhaust setups F bodies came with. it seems to me there are four. I'll list my best guesses from reading this forum a few months

How about you guys help me fill the others in using the same format as EXHAUST1

EXHAUST1 1982-1992 LG4/LO3
Downturned cast iron manifolds with 2" outlets leading to 2" y pipe which goes into a single cat through a 2.25" inlet then out from the cat through a 2.25" outlet to a 2.25" intermediate pipe which dumps into a single 2.5" inlet/dual 2" outlet muffler into dual 2.00" tailpipes which exit the rear of the car.

 

ummm no the day someone tried to stick some 2 inch tail pipes on my car and say that is factory is the day i am gonna take the muffler shop guy and wrap him around a telephone pole

 

OK, are you saying something is wrong in the description of EXHAUST1? you do realize that is just one of many combinations of exhaust our cars came with as best as I know it. If I'm wrong, tell me. If you know another combo, list it. Lets build a table of these stock exhaust combos which we can use for all kinds of purposes.
Mike

 

yeah we need this in a table on the site.

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1985 Camaro IROC-Z LB9

1989 Pontiac Firebird
Formula W6S LO3 TBI 305
-180 degree stat
-Hooker Cat-Back

[This message has been edited by Keith5 (edited November 13, 2000).]

 

| ENGINE |Exhaust | Y | Cat. Cvrtr | Int | Muffler |
|Year/Size/Type|Man.Out | Pipe | IN / OUT | Pipe | IN /OUT |
---------------------------------------------------------------------
All, 305, LG4 2.00" 2.00" 2.50",2.50" 2.50" 1-2.50", 2-2.50"
All, 305, LB9 2.25" 2.25" 2.50",2.50" 2.50" 1-2.50", 2-2.50"

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1988 Camaro Sport Coupe305TBI-4spdAOD-2.73open in "bought stock" condition. That'll change if it stays around here much longer

 

Interesting, since the stock Y-pipe on my '87 IROC with a 305TPI and A4 tranny had a 3" outlet, the converter was 3" in and 2 3/4" out, the cat-back was 2 3/4", and the tailpipes were 2 1/2". I'm positive the Y-pipe was 3" since my stock cat fit over both the Hooker headers Y-pipe and the stock one... The 350TPI's were also the same as this setup. The later 305TPI/A4 cars had the smaller Y-pipes and cats though as I've seen on a friend's '91 Z28.

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Greg Westphal
'87 IROC 305TPI/A4

 

OK folks, is this better.
look, iam definitely not trying to look like an expert on this, actually more like a reporter.

This will help those of us looking to replace our exhaust in knowing what all has to be replaced to get a great exhaust system built up.

| ENGINE |Exhaust | Y Pipe | Cat. Cvrtr | Int | Muffler |
|Year/Size/Type|Man.Out | pipe/FLG | IN / OUT | Pipe | IN /OUT |
---------------------------------------------------------------------
1987 305 LB9 2.25" 2.25" 3.00" 3.00" 2.75" 2.75" 1-2.75", 2-2.50'
1987 350 L98 2.25" 2.25" 3.00" 3.00" 2.75" 2.75" 1-2.75", 2-2.50'
83-85 305 L69 2.25" 2.75" 3.00" 3.00" 3.00" 3.00" 1-3.00", 2-2.50"
All, 305, LG4 2.00" 2.00" 2.50",2.50" 2.50" 1-2.50", 2-2.50"


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1988 Camaro Sport Coupe305TBI-4spdAOD-2.73open in "bought stock" condition. That'll change if it stays around here much longer

 

82-92 LG4, L03
2" manifolds, 2.25" y-pipe, cat, midpipe, muffler, tailpipes. The cat-back could also be 2.5", i've never measureed, but it's small.

83-85 L69, LB9
2.25" manifolds, 3" oval y-pipe and cat, 2.75" intermidiate pipe, 2.5" muffler and tail pipes

86-92 L98, LB9
2.25" manifolds, 2.75" y-pipe, cat, midpipe, 2.5" muffler and tail pipes

89-92 L98 and LB9 w/G92 axle
2.25" manifolds, dual 2.25" headpipes and cats, 2.75" midpipe, 2.5" muffler and tail pipes.

89 Transam GTA, a few bolt ons

 

I forgot a couple things.

y-pipe on LG4 is 2.5", cat is still 2.25", and i'm, pretty sure the cat-back is 2.5"

90-92 LB9 auto
same setup as LO3

 

I'm not so sure about that 2.5" intermediate pipe on an LG4. I've got an 85 and replaced the stock muffler with what was supposed to be a direct bolt in, 2.5" inlet. Needless to say it didn't fit. Everything from the converter back is 2.25", at least on my car. I'm not sure if all were equiped the same, it seems like there were a lot of different combinations.

 

That's why I said I wasn't quite sure. I've seen both, but some may have been stock and some aftermarket. Either way it's really small.

89 Transam GTA, a few bolt ons