C2 Carb ( GM3906631)

[John Thomas]

I recently had my Holley 3810A rebuilt by an "expert". Now I am having problems. Motor is 327/350. Does anyone out there know the OEM dia of the needle seat? Also, the "expert" replaced my throttle plate assembly (the old one was cracked) with an assembly he had. I have a feeling it was from a std. 4150 Holley. For some reason I remember small holes drilled in the primary butterflies of the original. Is this fact or am I imagining things?

[Rich G.]

Re: C2 Carb ( GM3906631)

I have a 3367 (list) holley which is in a box after rebuild. It is a service part, not original. It has no holes. As far as the dimension you ask about, I wouldn't know where to look. Sorry.

Rich Giannotti

[John H.]

Re: C2 Carb ( GM3906631)

The original 3810 didn't have holes drilled in the primary butterflies - this is a modification made by some folks with radical aftermarket cams in order to admit extra air at idle to get their engines to idle on the idle circuit instead of on the transfer slots.

[Clem Z.]

Re: C2 Carb ( GM3906631)

3810 carb, jets primary #65,secondary plate -22,#65 power valve,.025 squirter,.097 needle and seat

[Mike McKown]

Re: C2 Carb ( GM3906631)

John:

What kind of problems are you having? If you are having idle problems, may be what John is talking about.

Mike