Holley OE HP 4160 carbs

[72RoadrunnerGTX]

I’m curious to hear how many here are still running a ’70-72 OE HP Holley 4160 650CFM carburetor and what your current experience is with them.

More specifically, the ’72 U-code version, List numbers R6252 thru R6258. Stumbled across a R6255 recently in pretty good shape, rebuilt it and have been testing it on a slightly modified 400. The R6255 is a federal production automatic with N96, fairly rare I would assume.

 

[Woodruff Carbs]

Holley’s first 3 circuit carburetor.

 

[72RoadrunnerGTX]

Yep, the transfer and idle circuits are completely separate. Ran a R4367 on a ’70 383 Road Runner 4-speed back in the day, had a slight off-idle flat spot but otherwise ran well when it had fresh gaskets in it. I’m finding something similar with this one, exploring ways to get at the restrictions.

 

[flypaper]

someone I know was looking for a very long time for a 6252
for a very original lo mi car.
very hard to find

 

[RJRENTON]

IMO...
I had a 71 Mopar Satellite with a 383 /335 HP engine and used a Holley Model 4160 R4668A as the car had AC and the carb had the hot idle compensator sydtem AND the down leg secondary booster venturi and was rated at 750 CFM. it also had the reverse idle (backward idle) mixture system which was a fixed fuel feed and an adjustable air bleed circuit which the screw was turned IN to richen the idle mixture (REDUCING) air flow. Fixable by interchanging the primary metering block with a normal Holley metering block.
The 4160 design is fine but with the secondary metering plate, a PITA to tune. Substitute the fixed jet plate for one with removable jets of the equilivant AREA and things will work out great.
BOB RENTON

 

[72RoadrunnerGTX]

Stumbled across another one, NOS 6515. Build date in ’74, designed as replacement to several OE HP applications. This one has a two-circuit primary design.