I went with DynoMax Ultra Flow Race Series Mufflers and 2 1/4" Aluminized pipe from manifolds to mufflers and S/S from mufflers back (polished the tips, looks great). These mufflers are similar in looks to Flow Masters (welded seams) but are available in a length more suitable for 1st Generation Camaro's as 2-chamber Flow Masters fit well but are too loud for some people and 3 chambers are a tight fit. The end result is a deep, throaty mean sound that is great. I have Flow Master 3-chambers and 2 1/2 " aluminized and headers on my '69 SS and the system I just described on my '69 Z/28 sounds better!
1969 RS-Z/28: Matching #'s DZ302, M20, 3.73, Tuxedo Black, Deluxe Black Interior, Factory Tach, Clock and Console Gauges, PS, Rear Defrost, Spoilers, ZL2 Special Ducted Hood.
'85 Z/28, 355 TPI w/ Crane Compu-Cam 2040, Crane adjustable fuel pressure regulator, 22# Injectors, TPIS Airfoil, K&N filters, Hypertech ThermoMaster Stage 2 Chip for '85 Vette, 160 Degree Thermostat, DynoMax Cat Back Exhaust, Rebuilt/Updated 700R4 w/shift kit, 3.23 posi rearend.