I noticed on another post you suggested a holley 3310-2, but at summit or jegs they don't list it that way. What carb is that exactly?

This carb is 750 vacuum secondaries,manual or electric choke.
DDeennis is correct,he posted the Holley list # which is how they are identified.

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=826&prmenbr=361

Thank you 4speed - Have an idea of the best secondary spring and jet combo would be to start with?

2nd from lightest,which is the tall yellow or use the purple spring..3rd lightest.
Leave the jetting alone..it's 72 primary,which is fine.

thanks again 4speed!
I'm sure I will need your help again soon! :rolleyes:

i totally agree with mr 4 speed on the spring and jets....

i myself have found the best performance with the tall yellow spring just over 1.5 mph and about a .15 sec quicker over the standard holley spring on my 396....73 jet seems about right.....around 67 jet is too lean i feel a surge at cruise........i have tried fatter jets up to 80 at the track in the primary. but have seemed to fall off with 76 jets and bigger. going to try a few jets smaller in front since i have the rear jets closer for max power.

i like the 3310-2 carb a lot .....first thing i like to do is trash the metering plate in the rear.....i install a block so i can change jets......right now i have gotten my best mph from yellow tall spring, 80 rear jets no power valve,73 front jets with a 8.5 power valve. of course i "modify" all my carbs i cut the choke horn off, sand the butterfly throttle blades thinner and sand the shafts down as well and use flat screws to help to increase air flow, and deburr and casting flash....

the 3310-2 is the second version of the 3310 holley carb series..the orginal 3310 was a 780 cfm carb. each time there is a change to the carb holley added -1,-2,-3,-4 for each revision to the original carb number.