C2 Exhaust System 327/Powerglide

[Jim T.]

Re: C2 Exhaust System 327/Powerglide

My 68 L-79 has the factory installed 2" exhaust cast iron manifolds with the fresh air injection tubes and the exhaust pipes begin as 2" connected to the ehaust manifolds but enlarge inches from this connection to a 2 1/2" exhaust pipes all the way to the muffler inlet. Did the 70 350/350 and the LT-1 use this same 2" to 2 1/2" set up. I know the LT-1 had air injection.
Mufflers with some sound. I replaced my 68's mufflers with Walker original style replacement mufflers. I like the sound of these mufflers expecially when the convertible top is down going through the gears. These mufflers have a lifetime guarantee and they have been on the car for over 18 years. The outside finish has not rusted over and are just a good product.

[Duke W.]

Re: C2 Exhaust System 327/Powerglide

Your pipes are mashed down more at the strut rod bracket than C2s due to the difference in the C3's strut rod bracket geometry to lower the rear roll center. (The lower rear roll center yielded less camber change, deemed necessary because of the wider tires and create greater understeer bias.)For '69 all Corvettes had 2" pipes, but they went back to 2.5" at least for SHP SBs and BBs for 1970, but 2" manifolds continued for SBs.

The last year for 2.5" SB manifolds was 1965 - 300 HP with manual trans. and SHP/FI.

Duke

[Paul L.]

Re: C2 Exhaust System 327/Powerglide

Duke,
Dynomax lists a Super Turbo and an Ultra Flow. Which one do you recommend for a "little" noise?

[Duke W.]

Re: C2 Exhaust System 327/Powerglide

Look around on their web site for flow and noise data. In my old paper catalog they list flow data for all muffler part numbers and state that an Ultraflow of similar length and same size inlet and outlet nipples as a Super Turbo is less noisy even though it has a higher flow rating.

Duke

[Joe L.]

Re: C2 Exhaust System 327/Powerglide

Jim-----

ALL 1966 and later small blocks that were originally built with 2-1/2" exhaust used the 2" to 2-1/2" section below the manifolds on the forward pipes. That's because after 1965, the 2-1/2" outlet exhaust manifolds were never again used on small blocks.

For 1970, the only small block that used 2-1/2" exhaust was the LT-1. The base engine and L-46 used 2" exhaust, just as they had in 1969. For 71 and 72, as far as small blocks go, the base engine used 2" exhaust and LT-1 used 2-1/2. For 73-74, base engine used 2" exhaust and L-82 used 2-1/2".

All 1965-74 big blocks used 2-1/2" exhaust EXCEPT 1969 which used 2" for all big block engine applications.