holley base plates

[cwhubb]

I want to change out the base plate on a holley 950hp to one with a vacuum port, its a 4150 series and in reality flows 830 cfm, can I use one from an eight fifty and will it affect the cfm?

 

[Meep-Meep]

The original 830 (list 4788) is an 850 main body with an 800 throttle body chamfered to fit the larger main body bores. I don't know if what you have follows the same rules, but if it does then I don't see why not. Just chamfer to blend the two bore sizes.

 

[lewtot184]

i would think a 4781 base plate would make for a replacement. i'm curious; doesn't the intake manifold have place for a vacuum fitting?

 

[cwhubb]

yes it does I meant the pcv valve sorry

 

[lewtot184]

vacuum for the pcv valve doesn't necessarily have to come off the carb. the tri-power corvettes didn't have a carb provision but used a threaded port directly off the manifold for a pcv vacuum source. just an option.

 

[mopar12372]

pcv should have direct manifold vaccuum weather its on the carb or the manifold it dosent matter .

 

[cwhubb]

cool, I ordered a new base plate with the port, I found out on the 4150's 750,850,950,1000 all interchange

 

[lewtot184]

750's and 830's have a different throttle bore size. 1 11/16" vs 1 3/4".

 

[cwhubb]

scratch the 750 then thanks for the info Lew