78RedShark

I need some advice.

I want to get straight pipes to get that cat out of there. Should I also get headers? What about replacing the original cam?

I've been told that unless I put in headers and a new cam, it's not worth it to just put straight pipes.

What should I do? :confused:

Ganey

See my exhaust topic. http://www.corvettefaq.com/c3/ganeyexhaust.htm

Go to duals & replace cam which L-48 needs badly. Headers rec., however are optional.

Anyone w/ the exhaust topic link on this forum could post it.

NEW77GUY

Ganey, i'm also in need of an exhaust for my 77 stock L-48. I understand the headers point (i'm nowhere near 300 yet...) so i guess i'll wait on those for now. Are you saying that i should do the cam though as well? I read that entire exhaust link. I actually have a hook-up in the "inspection industry"....but i still don't feel like being pulled over and busted just the same. Right now i NEED from the Y-pipe on back- but i'm interested to hear anyone's suggestions! Secretly though....i really want sidepipes- (all performance issues aside.) :D :D

nunus79

FWIW, based on memory (I don’t have my log book handy), I’ve listed a series of modifications and resulting 1/4 mi numbers that were done to my once stock 79.

Installed L79 cam (327/350hp), 2000 rpm stall converter, super turbos mufflers - 15.5@87mph

Performer intake, rebuilt Qjet, Rhoads lifters, advance cam 4deg - 15.2@88-89mph

Gutted cat - 14.9@91-92mph

Sportsman II heads - 14.2@97mph

Richen Qjet - 14.3@96mph

Replace 2-1-2 stock exhaust pipes w/hedders & 2.5 pipes - 13.9@99mph

tnt76vette

Based on my experience, removing the 2 Y-Pipe system and going to ANY type of true dual system (mufflers or chambered pipes) will thoroughly impress the seat of your pants on acceleration :D . Truly believe that one mod alone gave me just as much increase in HP & TQ as my cam and dual plane intake mod did :lol: . If you want "bang for the buck", get rid of that stock system...... :cheers: :cheers: :cheers:

79er

Will if you can afford it, yes do everything, but the cam and dual exhaust should come before headers. Do note that the engine will love a set of header after replacing the cam and putting in dual exhaust. :chevy

nunus79

Tom
Could it be that getting rid of just the catalytic converter/lo-perf mufflers and not the entire 2-1-2 system caused the positive results? ;) :troll

tnt76vette

Reply to Nunus79: sure could have my friend...but thats something I'll never know for sure....guess I should hold back my enthusiasm just a tad on true duals huh? NAH!!!!! :jester

Ganey

Definitely do the cam. If you want to keep the Y for now you could replace the mufflers w/ straight pipes. Have suggested this before & several C3 & 4 guys have done it & are very happy, the single ex./cat. quietens enough for many.
Comp Cams XE262 is good min. for 4 spd., CS268H is similar & works w/ stock valve springs. Either are much better than the L-48 cam.

You might want to see 77Facts on my website.

NEW77GUY

Thank you Ganey.... :cheers: :chevy