Holley 3810 vs 3811

[Gary C.]

What are the main differences in a Holley 3810 and 3811? Would a 3810 "function satisfactorly" on a 390HP 427?

[Joe L.]

Re: Holley 3810 vs 3811

Gary------

The only difference that I can find relates to some difference with respect to the throttle body assembly ("base plate" with throttle valves and shafts). Although I can't say what the difference is, I believe it to be very minor.

Both carburetors are rated at 585 CFM and both even used the same primary jetting. Although the primary metering blocks were STAMPED differently, I can't find any difference in the blocks or the installed jets. The SERVICE block and jets for both carburetors are the same. The secondary metering blocks are the same. Of course, it's no problem to change jets, anyway.

I feel very confident that a 3810 would function perfectly in place of a 3811.

[Joe L.]

Addendum

I should have said secondary metering PLATES. The 3810 and 3811 are model 4160 carburetors which use a secondary metering PLATE and not a block. Also, to be clearer, the jets are applicable only to the primary metering BLOCK. There are no replaceable jets in the secondary metering plate; the plate must be changed to change jetting.

[Gerard F.]

Re: Holley 3810 vs 3811

Gary,

To add to Joe's info, the 3810 uses a #22 secondary metering plate and the 3811 uses a #17 secondary metering plate. Not sure what the exact difference is but I think the #17 is for the bigger engines and gives you a bigger shot on the secondary side. Not sure you can find a #22 plate anymore (I've tried)but you can find a generic replacement for the #17.

Jerry Fuccillo
#42179

[John H.]

Re: Holley 3810 vs 3811

The #17 metering plate has a .073" orifice (equivalent to a #70 jet), and the #22 metering plate is leaner, with a .065" orifice (equivalent to a #65 jet).