Tuning for Holley 600 on a street ported 12a?
 

Iam looking for any info on tuning a Holley 600 on a street ported 12a.
My only starting point I have is, to start with 58 jets for the primaries
and 56 jets for the secondaries. Any info will help. Thanks

I have changed out my primaries to 62's. My car is running alot better with the richer primaries and I am thinking about trying 65's, like my secondaries. I have also found out the 600's with th vac secondary dont have adjustable air bleeds, I now need to look into how to tap them and make them adjustable. Good thing I have an extra 600 laying around! I think since the air bleeds are supposed to richen higher rpms it should make my engine really open up the way it should?

Vacum sec. kinda sucks. I always rig it so sec. opens mechanically. I always jet the primary as lean as possible before it starts stumbling for response and milage. Than fatten up the sec. to where it sputters on high end then gradually lean out the sec. to where it feels good. The accelerator pump cam will be a bitch because every motor is different and it has to be ground to tailor each motor. I got 21mpg hiway and 218 RWHP out my 700 double pumper with 14/1 AF just by feeling it. On the edge of too lean but that is where it likes to run.

Iam sorry I havent read you post sooner. What mods do you have on your engine and what kind of port? 218 to the wheels sounds good.

My jets are now at 59's prim and 65 sec.

813, you can get a kit that replaces the metering plate with a metering block like the primaries. Center hung floats probably wouldnt be a bad idea either since Holleys are mounted wrong way on a rotary.

Yeah, got the block. Side hung floats would be nice too, but cost to much for a carb that Iam not sure is going to be the best performance carb for my engine. I dont want to throw a bunch of money into this carb than decide I need to take out a loan to get a RB one or webber or go back to a nikki and get it modded?

Look on ebay for a junked up carb that has what you need. You might get it cheap. I got a 3310 750CFM Holley, modded for dirt track oval racing for $70. Had all the goodies, was just filthy.

I meant center hung floats.

Iam not familiar enough with Holley's to know which ones I can buy to use the parts on my carb. I have only been getting to know the Holley for about 6 months now?

I have heard befor that notched floats and jet extensions are supposed to work like the center hung floats? Do you know if their is any truth in that?