Here's some info on Carter carbs I dug up.
CFM Model Venturi Diameter Bore Diameter
primary secondary primary secondary
400 AFB 1 1/8 1 1/4 1 7/16 1 7/16
500 AFB 1 3/16 1 1/4 1 7/16 1 11/16
575 AFB 1 1/4 1 9/16 1 9/16 1 11/16
625 AFB 1 3/16 1 9/16 1 7/16 1 11/16
750 AFB 1 7/16 1 9/16 1 11/16 1 11/16
800 TQ 1 3/16 2 1/4 1 3/8 2 1/4
1000 TQ ???? 2 1/4 1 1/2 2 1/4
9000 Series AFB Code Deciphering:
Base part number is 9000 and the last three digits refer to flow
rating. Therefore a 9625 means a 625 CFM AFB carb. adding 0
(i.e. 9625) means it was originally set-up for a Chevy style linkage,
adding 1 (i.e. 9626) means its a 625 for a Chrysler application,
adding 2 (i.e. 9627) means its for a Ford application. Adding
10 means provision for EGR.
The ThermoQuad flow ratings may not be directly comparable with Holleys.
In a 'Performance Clinic' column by Dick Landy in the August/September
1994 issue of Mopar Muscle (page 9), Dick states:
"There are two basic ThermoQuad Carburetors: one with 1 3/8" primaries
and 2 1/4" secondaries for the 318 and 340 (A) engines and a Holley
comparison CFM of 650 CFM. The second one had 1 1/2" primaries and
2 1/4" secondaries with a Holley comparison CFM of 820. It's used with
some 360s and all the 'B' engines. Actually, Carter called this one a
1000 CFM unit. Their airflow numbers were measured differently than
Holley. Also, some ThermoQuads had the secondary air-door limited,
which also decreased the CFM."
I don't know if the above is true or not. The reference material I have
says both Holley and Carter used the same pressure drop to measure
4 bbl airflow.
Later,
Dan Jones
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