Welcome to the Corvette Forums at the Corvette Action Center!

do i need to upjet my carb to match new exhaust?

U

uk mark

Guest
Hi Everyone,
I have recently fitted new Headmann headers and a stainless steel exhaust system which has got rid of he catalytic converter and made the car sound a lot better!
After running it for 100 miles or so i checked the plugs and they are very white in colour which suggests that the engine is running lean.
If anyone has done anything simular or has info on Rochester M4MC carb then i would be grateful for any advice.

Many thanks,
Mark.
 

motorman

Well-known member
Joined
Mar 7, 2002
Messages
849
Location
pa
Corvette
2008 Crystal Red Tint Coat
what is the # stamped on the side oof the carb?
 
U

uk mark

Guest
upjetting

Hi Motorman,
The carb is a Rochester quadrajet with the following number: 7045222 R6 0295.


Thanks.
 

motorman

Well-known member
Joined
Mar 7, 2002
Messages
849
Location
pa
Corvette
2008 Crystal Red Tint Coat
mark,i would try a "DA" (.040 dia tip) to replace your secondary rods which are CH (.057) to richen up full throttle. your pri jet should be a # 72 and i would try a #74 for starters.
 
U

uk mark

Guest
Thanks Motorman,
It'll take a while for the bits to get here but I'll let you know how i get on.

MARK.
 

motorman

Well-known member
Joined
Mar 7, 2002
Messages
849
Location
pa
Corvette
2008 Crystal Red Tint Coat
these parts can be gotten from a speed shop that handles edelbrock . they list a .041 sec rods part# 1951 and .074 jet is part# 1974
 

JHL

Senior Member
Joined
Oct 24, 2000
Messages
403
Location
Everywhere
Corvette
81 4 speed
Hi Mark

I bought some jets and rods for a quadrajet from Speed and Spares America - 01372 745747. They had them on the shelf and they were only a few pounds. Alternatively I have used John Woolfe Racing for some bits and found both places very helpfull and reasonably priced.

J.
 
U

uk mark

Guest
Thanks for the info JHL,
The car looks excellent. I'll check out the website.
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom