Holley 390 Power Valve?

[Anonymous]

Does the Holley 390 (#8007) have a power valve? And if so, can it be replaced with a two-stage power valve for use in a truck?

 

[CZLN6]

Howdy '74trucker:

Yes, Holley #8009 have a Power Valve. They are also a vacuum secondary 4 barrel. I don't know about the two stage PV. I've neverused one.

Adios, David

 

[Anonymous]

Is the power valve used in a Holley 4150/60 (600cfm) the same kind as one used in a #8007 (390cfm)? Interchangeable in other words?

 

[CZLN6]

Howdy Back:

Yes.

Adios, David

 

[Anonymous]

Next question:

On the jets themselves, what does the inscription "512" mean? I'm sure it relates to the size of the jet, but is it Holley code for a certain kind of jet?

 

[wsa111]

74 trucker, holley uses close limit jets on emission carbs & some other carbs where they want a more precise mixture. The 512 jet is a 51 jet in the middle of the flow band.
For example a 511 is on the lean side,a 512 is in the middle & a 513 is on the rich end of the 51 jets flow. There is a 1.5% difference in flow between each of the jets in a flow band. Hope that answers your question.
V/R William