[Singleton]

Looking for recommendations for jet sizes for both center and end carbs on a 350.

65 tripower set up.

1969 350, (actually 359 cid after .030 overbore), 8.0 compression, stock 47 small valve heads, factory 066 camshaft installed straight up, stock exhaust manifolds and pipes.

Going in a 64 Lemans ragtop, TH350, 2.93 rear.

I'm thinking a 58 or 60 jet for center?

Also, anyone have a unmodified venturi cluster for the center carb?

[Tom Vaught]

Dick B might know better but as a first guess 60 on the center carb and 63 or 64 jets on the outer carbs.

Tom V.

[Dick Boneske]

I think 58's would be a good staring point for the center carb. I've used 60's in my 434 cu. in. Tripower, and it didn't act lean. It runs better with 62's.

In the end carbs, I'd go with 66. Most 389's used 68 jets from the factory in the end carbs, but with 10% ethanol, I think 66.would work well.

[Goatracer1]

If it helps at all the 347 and 370 tripower engines used pn 7008661 .061 jets in their center carbs. Their end carbs were smaller so they wouldn't help you. For anyone who cares the pn was 7002656 foe ft and rr carbs.

[Singleton]

Thanks for the replies.
I had this set up previously on a 440 cube engine that ran pretty well. I believe I used 64 or 65 jets in the center with 70 or 72 in the outer. I also modified the center Venturi cluster by enlarging the idle and main air bleeds, so I need to correct that also.
I'll be using 100% gas, it's pretty common at the pumps around here. The ethanol stuff causes me nothing but problems.

[Tom Vaught]

Originally Posted by Goatracer1

If it helps at all the 347 and 370 tripower engines used pn 7008661 .061 jets in their center carbs. Their end carbs were smaller so they wouldn't help you. For anyone who cares the pn was 7002656 foe ft and rr carbs.

I was basing my recommendation off of the 370 tri-power carbs of the old days and then took one jet size off for the 350 engine. Did not realize the 347 engines also used the .061" jets. Thanks for the new info.

Tom V.

[Dick Boneske]

Yes, the '57 347 used 61's and the '58 370 used 60's. The same center carb was used on both engines, so it's strange that the larger engine used smaller jets.

As Goatracer1 says, the end carbs were smaller, so jet sizes are not comparable to the larger end carbs, but both the '57 and '58 engines used 56 jets in the end carbs.

I'll stick with the recommendation of 58 in the center carb and 66 in the ends. If it stumbles, you may have to switch to 60's in the center carb, but I doubt that.

[Tom Vaught]

Either way a good starting point #58 jets and jets on the center carb are easy to change.

Tom V.