I need a place to start with jets on my new motor. The carb is a holley 600 cfm double pumper with the choke tower removed and smoothed. it just got a rebuild. motor specs are as follows:

It has 2.02 1.60 heads. The heads have screw-in studs and guideplates. They are also ported and polished. It has a 275° duration camshaft. The engine is fully balanced and blueprinted, and the deck has been trued. Its got side polished shot peaned rods with ARP bolts. Keith Black flat top pistons. I'm running a Weiand Stealth intake manifold with a Holley 600 CFM Double Pumper carb, without the choke tower. The car still has the stock converter and tranny, but it has 3.73 posi in the rear-end.

of course it has headers and full 3" exhaust. that 275* duration is advertised duration. the cam has .455 lift. what jets do yall think i should start off with in the tuning process. also what timing do yall guys think i should start with in the tuing process, i set the timing at idle, should i be doing total timing instead? what timing should i start with at idle?

thanks
brady

 

Does this carb have primary-only power valve, primary and secondary power valves, or no power valves?

That stock stall converter will probably cause you to curse this double pumper for as long as it takes for the engine to get over its bog and get into the power band. But, the good news is that a 600 is small enough that the bog length will be reduced somewhat.

 

primary only i believe. what jets should i put in it to start off with???

 

Try 70's in the primaries. If no power valve in the secondaries, go up about 6 sizes for them.

From there, it's tuning. In the '57, I followed the 6-sizes rule all summer - tonight I went down two sizes in the primaries and up two in the secondaries, because it had been rich in cruise but seemed happy WOT. The 10-size split seemed to work out well.

Of course, the powervalve is part of the tuning process, too. I went up two numbers from what came in the carb. Again, it's very happy right now.