On my '66 396, I'm changing from a 4777 650 DP to a 6210-3 spreadbore DP. My question is on jetting. The car ran great with the old 4777 with 65 primary and 76 secondary jets. Plugs are a little dark, so it may have been a little rich. The new/old 6210-3 has 209 (stamped on jets) primaries and 83 secondaries. Should I use the jets from the old carb, or?
I don't understand the 209, doesn't sound like jet #'s to me?
The reason I'm changing to the spreadbore is to get rid of that stupid spreadbore to squarebore adapter.
This is my set-up:
Original 396/325; 3.07 non-posi rear -- soon to be 3.73; TH 400, headers, Comp Cams 280H-10 High energy: .520 lift, 230 duration @ .050., factory Q-jet intake, bored .040 over, 10.25 to 1 compression or thereabouts.

I'm getting ready to fire this thing up after 16 years of sitting, so I'm just trying to get everything as right as possible beforehand.

My goal is a nice weekend cruiser, no racing. I may take it down the strip a couple times just to see what she'll do, but that's it.

Thanks a lot for any help!! :D

Dave

I think they are 63 jets stock in the front. I know what you mean about the adapter plate, the 4777 is a much better carb though.

Dave

The car ran great with the old 4777 with 65 primary and 76 secondary jets.
Thanks a lot for any help!! :D

Dave

If it ain't broke, don't fix it.

Any help from you Holley sages out there? I'd like to figure this out so I can button it up. Thanks.

Dave

Ok the stock jetting for your 6210 is,,a 602 you read it backwards, which is a 62 jet size and 83's in the rear. I would leave the stock jetting in there and go from there.

Dave

Emissions carb close limit jets? I suppose I could look in the book. Someone else will chime in. Tom's good on this subject.

Thanks. I guess I'll kit it and leave the jets as-is for now.

Dave

Looked it up they are the close limit jets & 602/83's are what they came with. The jets are the same except for the flow tolerance, if you need to jet different you can use standard jets. The 602 is a 60.

Jim, thanks, I appreciate your help. :)

Dave