I am about to install my new (to me) 600cfm 4160 holley carb. I know that a 1" 4 hole spacer is recommended so that is what I will use. However, what vacuum rated power valve should I run? Should I run a power valve at all? The engine it is on is a stock port 12a with straight pipe (2 1/4") all the way back from stock header to magnaflow muffler. Also, anyone have a recommended jetting for me to start with? My carb has a merting block on the primaries (65s currently) and a metering plate on the secondaries (#8). Any other recommendations from those out there using vacuum secondaries or a similar setup? Thanks.

 

i think RB removes the powervalve when they "modify" their carbs. as for the jets and such, search for Holley jets, etc. there was a recent thread regarding non-RB Prepped carbs.

what fuel pump are you going to use?

also, vacuum secondaries dont seem to work out so well for most people using the holleys on these cars, jam a screw in it and make them mechanical.. its all thats worked for me.

g'luck

 

what intake r u using that u need a spacer?

 

star with 62 for the primaries. i might have a couple. also leave the power valve in. if you wanna try to block it off i have the block off. it didn't run as good for me. i went wth the lowest power valve number i could find. think it's like a 3.5. also don't try the screw thing. change the spring t the white or little yellow one. and you need to change the cam to the green one. there is a couple other little tricks to get them to run better. i can't believe with all the work you spent getting the other carb to run good and that you are going to sell it you are going to put that one on. save it.

 

In my next project I will be going with a weber side draft setup which is why I might as well get this one prepped and ready for a buyer. Also I am using the rb holley manifold which is why I am going to use a spacer, from what I have read this will give better secondary performance.

 

I did a jetting post on this. Do a search for my name and holley.

 

If you are running a non RB modified Holley you should run an open spacer, not a 4 hole. And run the power valve, a 3.5 or 4.5 like he said. A 600 will be big on your stock port 12a. A large open style spacer will weaken the signal to the boosters, making the carb easier to tune on your rota.