Need help with recipe

[69gscal]

Here's my set up.

Full weight, 69 Buick GS.
400ci engine @ 9.5 cr.
cam; duration= I 228, E 246 @.050 with 118 lobe seperation.
                         .490 lift with 1.6 rockers on both I and E.
3.64 gears
TH400 with shift kit
Unknown convertor
2.5inch exhaust all the way back after ported exhaust manifolds.

Carb is a stock 69 Buick GS 400 7029242.
Idle Tubes= .032
Idle Down Channel= .047
Main Air Bleeds = .040 (Air Horn)
                             .070 (Body)
Idle Air Bleeds= upper (body) .050
                          lower .078
No Bypass Air
No holes in throttle plates.

There are no revisions for bypass air and a vacuum source in the main body where I'd need to add it. It won't be an option so I'll need to add holes in the throttle plates.



My thought is to start by adding the holes in the primary throttle plates (.060) and increase the idle tube to .037.  This carb would not idle in anything other than park the only time I tried to run it and it would burn my eyes.


Would this be a good starting point or would I be better off resizing a few of the holes and starting with Cliff's #1 recipe. I don't excpect to get it the first time and have plenty of time to work with it till I get it right.


Thanks,

[Cliff Ruggles]

Idle bypass air is easily added to the carb if you choose to do so.

That cam isn't all that big for a 455 engine, so before adding bypass air I'd open up the idle tubes and increase the idle down channel restrictions.  If you still find that the carb has nozzle drip, or lack of control with the mixture screws, some bypass air will be needed.

Has the carb's throttle body been rebuilt with bronze bushings?

Did you install one of our rebuild kits with the upgraded components?......Cliff

[69gscal]

Thanks Cliff.

It's a 400 engine and I have your full HP kit and bushing kit to do both. I originally planned to add the bypass air, but there is one vacuum source that concerns me below where I'd have to drill in the main body. I'll see about taking a picture and posting. If I can add it, I'd much rather go that route.

Aubrey