id give it the sink test

or what i di is the bat test,,then the .500 mag test..

This oddball Holley isn't at the top of my wish list either, but that's what I have for now.
I did find on the net that they were originally designed for Ford by Holley. Then Holley started making their own version later.

Anyway, got it apart and the insides look pretty good. No corrosion at all.

I think the primary power valve has a ruptured diaphragm. I squirted some carb cleaner into one of the 2 holes and it appeared to be leaking thru to the other side of the diaphragm. Didn't see any check valves to prevent power valve damage during a backfire. Must be pre 92.

The current power valves are 6.5's so I shouldn't have a problem finding them locally.

Does the power valve determination formula (manifold vac/2) apply to marine engines?
I haven't measured my vacuum yet, but I'm assuming it"s >13"...

yes,,i try to find a maximum vacume at a higher rpm and divide by 2 and that would be your power valve number..