----- Original Message -----
Sent: Tuesday, March 19, 2002 2:51
PM
Subject: Re: [Chevelle-List] Carb and
Headers
I think the best advice on selecting a carb is to look
at what GM did. Depending on how hot your 396 is, look at the carb
options offered on 396 engines, and match your engine (performance wise) to
what GM offered on their 396 engines. GM had 396 engines from mild to
wild, so find one that is close, and select a similar carb.
Double-pumper Holleys are (more or less) racing carbs, the fuel circuits are
quite rich, which matchs well with a big loping cam. I like spread-bore
Holleys for a daily driver. You can get them in Double-pump and Vaccum
secondaries. The DP carbs are better with performance applications and
stiff gearing, the Vaccum secondaries shine with those freeway flyer
gears. The Spread-bores also come in 650 CFM (small block
flavor) and 800 CFM for the big blocks. Spread-bores work well with
stock cams and mild performance grinds. They are Holleys replacement
carb for the Quadra-Jet, and do produce more HP. The down side is: the
Q-jet gets the nod for smoothness and driveablity. I put a Q-jet on my
wife's '67 Malibu. Note to self: It is important to keep the wife happy!
Ha-ha Here's how I would break it down:
Stock rebuild 325 HP 5000
RPM 750 Q-Jet (Vaccum)
Stock rebuild 350 HP 5500
RPM 800 Spread bore (Double pump or Vaccum
depending on gearing)
375 HP
6000-6500 850 Double pump (wild street)
7000-8000+ 1050
Dominator (Drag racing)
I'm sure that will "ruffle some feathers", but I think
that is correct,
Rob
'67 Malibu
'67 El Camino (in a basket)
----- Original Message -----
Sent: Tuesday, March 19, 2002 6:06
AM
Subject: [Chevelle-List] Carb and
Headers
My intake has a 600 Holley Carb, which I'm told
is going to be to small for my 396 engine. The guy working on my
engine suggested a 650 or 750 Double pumper or a 750 or 780 secondary Vac
(I think that was the term he used). Can anyone
give me some pros and cons of each. I am also going to install
headers, any recommendations. Thanks
Craig
69SS
