Hey guys, I have a couple carb spacers I want to test with. They are both HVH Supper Suckers spacers, a one inch, and a 2 inch. I know this will cause a lean condition, so my question how much jet do I need to add to start with, just don't want to blow the thing up testing. Thanks in advance.

When I expermented a while back I didn't see much difference on the EGT's with and without on the 2". That was on built 496's with Holley 950's and BG 850's. We started out just a couple jet sizes over on both carbs.

What size motor. That will make a difference as far as which one and how many.

540 ci motor, single plane intake, 1050 dom carb.
Thanks for the help guys.

Use them both for sure. Is one a four whole and other square bore? 4 whole on top and squre bore on bottom helps velocity. Cools fuel and increases hp band. We use 2 2in. We picked up great power on the dyno.

Both spacers are open, but C&C machined on the inside to a cone.
So if I go up at least one number on the jets I should be ok, and not running lean?

What size are you running now

91 square.

I wouldn't run any more than that. That's plenty for a 540.

Your 540 should like the one inch for sure and maybe the two inch. You cannot run both if they are the 4 tapered hole HVH.