bd hbt

I have a 62 with a 350ci engine. Not sure of the cam. Edelbrock 4 barrel and 340hp intake. Currently has headers (which are shot) and a 2 inch exhaust system. I'm intending to replace the entire system with 2.5" exhaust pipes with either new headers or 2.5" exhaust manifolds. What are your thoughts regarding 2.5" exhaust manifolds vs headers? Thx.

Plasticman

2.5" pipes will fit through the X-frame holes, but it is "close", and your exhaust guy must be "good". Getting the 2.5" over the rear axle can be a pain, and be careful where the brake line bracket (for the rubber hose) is welded to the rear axle (pass. side).

If the cam is unknown, then what are the idle speed and vacuum? If it is idling at around 600 and pulling 19" or more at idle, then the cam is pretty much "low performance". As Idle speed goes up, and vac. numbers come down, the "performance" level goes up. If you like to wind through the gears, then manifolds will hurt upper rpm performance in comparison to headers. If you don't wind past 6K rpm, you may never know the difference between the systems. And the carb may of been adjusted for the headers previously, and possibly need readjustment for the manifolds.

I have 2-1/4" pipes (they fit pretty nicely), with headers. WMF62 has 2.5" pipes with manifolds, and they are a much tighter fit.

Also, make sure the new pipes "exits" are the same length, as previous (too short of "exits" may cause exhaust gases to back flow up to the cockpit area).

Plasticman

Vet65te

John - Thanks for the reminder about the length/location of the tail pipes, I'll keep that in mind when I have a new exhaust installed. My 61 has a set of Hookers and some hosed up exhaust dumps all connected to 2.5 pipes. The routing of the 2.5 pipes has them making this annoying squeak and adjustments have only helped a little. I like the 40 series Flowmasters but am intending on finding a decent shop around Prescott to make a new system minus the (useless to me) exhaust dumps. If the muffler guy is sharp enough, I'll stay with the 2.5 pipes up to the mufflers but go with 2.25 pipes from mufflers on out.

Mike T - Prescott AZ

tach drive 61

my 61 came with headers .changing plugs was a real PITA .now running L79cam in a 327 stock bore , I use the 62 exhaust rams a set of NOS high horse engine pipes with crossover pipe provision. this year I will install the cross over pipe .the rest is 2 " and off road round mufflers . I don't think 2 1/2 would make much of a difference

DZAUTO

Mike,
Am I seeing a Richmond 5 or 6sp in your 61?

Vet65te

Hey Tom - Yep, the PO added a Street Richmond 5-speed a few years before I bought the Vette. Not my favorite (too rigid shifting) but it'll stay in there while I have other projects ahead of it.
Mike T - Prescott AZ

DZAUTO

I have a R5sp behind a W30 spec Olds 455 (468) in my Cutlass, and I agree that it is kinda stiff shifting until the tranny gets thoroughly warmed up. But so far it's been bullet proof for over 25yrs without being touched!!!

DZAUTO

Here is a link with my reply/comments about 2 1/2in exhaust for a 56-62 Vette. No question in my mind that 2 1/2in makes a difference if the engine is a healthier 327 or larger.

https://www.corvetteforum.com/forums...2-exhaust.html

bd hbt

Thanks to all for your thoughts. Since I'll probably not hit 6000 rpm ever, I think I'll go with the rams horn manifolds.