does anyone have any know anything about these 2 systems:
289-17495
Camaro/Firebird 1986-91, w/5.0L & 5.7L-4V H.O. $165.99
289-17484
Camaro/Firebird 1989-91, 5.0L/5.7L FI/MFI w/Dual Cats $169.99

preferably size of the intermediate pipe...i'm looking for an inexpensive cat back

 

Im pretty sure the top one is 2 1/4 and the bottom one is 2 1/2. The super turbo is quiet on stock motors, but flows like a motha. I got one of the old dynomax ultraflow 3" exhausts and it is freakin loudand supposively flows like 1k cfm. i think the volume depends on the motor.

 

Have this system on my 88. Fit well, good smooth bend pipes, aluminized with no rust after 5000 miles so far. Nice deep sound at idle and some sound at highway speed, not loud by any means. Maybe just a bit louder than stock. Front pipe is not quite 3", maybe 2 3/4?, dia but it's plenty big and fits the converter fine. Hard to get over rear axle though with the one piece front pipe. I had the whole rear apart on my car at the time so it was no problem for me. Think the tail pipes are 2 1/2 inch and look pretty much stock. This was my third Dynomax kit and they are all pretty well made that I've seen.

From Jegs web site:

289-17495
Camaro/Firebird 1986-91, w/5.0L & 5.7L-4V H.O.
Fits 1986-91 Camaro/Firebird, 5.0L/5.7L-4V H.O. and EFI (engine code F & code G). 3'' flare with loose flange connection to catalytic converter. (except 1989-91 dual catalyst.) Tail pipes exit opposite sides

 

does the system include the cats. also would these be a good sleeper setup

 

No "catback" exhaust includes the converter(s) that I know of. Is a pretty near stock appearance I think.