8BA carburetor

[Gerald cook]

I’m getting all sorts of differing opinions on power valve and corresponding jet size. I’m trying one of the recommended choices 49-51 jets and 8.5 PV I have also read I should run 6.5 PV for this jet size. I will see how my car runs with this combination. Gerald

 

[KiWinUS]

Most important is to get the correct style power valve. Many kits have Holley power valves in them which are incorrect and will not seal.

 

[40 Deluxe]

Most important is to get the correct style power valve. Many kits have Holley power valves in them which are incorrect and will not seal.

How do you tell them apart?

 

[kurt v]

Call Daytona carb

 

[tubman]

This is what Mr. Google says :

Physical and Design Differences

Sealing Surface: The original Holley 94 casting features a flat sealing surface. Modern power valves have a small radius at the base of the threads that prevents them from sitting flat, which causes fuel leaks unless modified.

Retainer and Spring Size : The brass spring retainer on an original vintage valve is narrower and the entire spring assembly sits further recessed inside the stem.

Well Clearance : Contemporary modern valves have a wider overall profile that can physically interfere with or hit the internal steps of a classic Holley 94 float bowl well without modification.

Here's the best picture I could find.