Hello All,

After finally getting my Offy dual intake, I'm getting ready to start asembly of the intake system. I am using the original BBS carb (rebuilt 2986SA) that was on my car, and another BBS (rebuilt 2986S) that I believe came from a '60 Desoto.

First Question: Offy sent (3) #6 lead shot that is meant to plug the air bleed holes in the bottom plate of the carbs. Looking at the carbs, it looks like there are two holes on the bottom of each carb. Which holes do I plug? All of them, one on each, or none?

Second Question: In reviewing past posts here, there is talk about INCREASING the main jet sizes. The person at Howell automotive that I talked to said the same thing...go with bigger jets. The Offy paperwork says to DECREASE the sizes. Another person said that I don't need to plug the holes if I go with bigger jets.

I have some old pamphlets and paperwork that I have collected over the last couple of years about BBS carbs, but they are mostly a break down of parts and instructions on doing exterrnal adjustments

Help me out guys! What should, or shouldn't, I be doing?

If I increase the jet size, what size do I go with?
Can replacement jets still be found?
How hard is it to do?

Thanks, again, for any and all input.

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Bill

'60 Dodge Dart Pioneer

Vivian

With 2 3 cylinder intakes, the intake flow thru the carb(s) is pulsed (with 6 cylinder it's pretty much constant)

With pulsed intake flow, you generally need to reduce jet size. So asis, you'll be running a bit rich.

Since that is safer, I'd just leave it alone for now
(plus jets for BBS carb are pretty hard to find nowadays)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

If I were putting in the effort to install the dual-1bbl setup, I forget about plugging off any passages or changing any jets, and would definitely leave those primitive early BBSs on the shelf as paperweights. A pair of late BBSs ('71 type) would work a whole lot better and be much easier to dial in to run well, and I'm not saying that only because I have a matched pair of brand new such carburetors available.

That said, if I were going to try to bull ahead with the early carbs, and I were bound and determined to change jets, it would definitely be in the direction of lean.

And there were no slant-6 engines in '60 DeSotos, or any other year DeSotos, except the '61-'63 South African-market DeSoto Rebel, a rebadged '61 Dodge Lancer.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

My experience with BBD's is the newer ones had different style metering rods. Do they use the same rods/jets as the BBS's?

If I ever catch any of these carbs at the JY I am going to grab them.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick