Now that I have a 3310 Holley back on my car (put a 750 double pumper on right after I installed headers) I was able to get some info reviewing my timeslips..
This timeslip is for my car when it had stock exhaust manifolds,stock 2.5" lead pipes,old 2 chambers Flowmasters (they're black,not even aluminized,thats how old they are) 2" tailpipes,and the 3310:

60' 2.056
330' 5.75
1/8 8.803 MPH 80.48
1000' 11.459
1/4 13.74 MPH 97.45


heres a timslip from yesterday,
I now have 1 3/4" primary,3" collector headers with 2.5" muffler shop lead pipes,the same old Flowmasters,and 2.5" mandrel bent tails,and the same 3310 on it with no changes:

60' 2.06
330 5.596
1/8 8.502 83.69 MPH
1000 11.03
1/4 13.20 MPH 103.4

So I would guess I basically picked up .537 and 5.95 MPH changing to the headers and larger tails.

Were both runs at the same track in simular weather?

yes,but about a year and a half apart..no other changes.

here's a change i had on my car when it had the 454 in it....2" primaries, 3 1/2" collector, 2 1/2" exhaust with flowmaster 2 chambers, no tailpipes, 3310 VS carb: 7.89@87mph. swapped on 3 1/2" exhaust with no tailpipes, with 3 1/2" Delta Flows and an 850dp it went consistant 7.30's with a best of 7.29@94mph. no other changes. exhaust and carb really woke it up. of course those are all 1/8mi times. it did take some tuning to get the car to the 7.89 with the original set up. first run was an 8.12@86. i changed secondary springs around everywhere, played with timing and rejetted the carb several times to get it to a 7.89. the 850dp was out of the box with no tuning other than adjusting the floats. i tried larger jets but it slowed down. never did try leaning it any though. it seemed pretty lean the way it was, judging by the plug color. i could not believe the carb and exhaust made that much difference.

What spring where you running in the carb?

the purple one. i tried all of the springs in the kit that were lighter than stock, but it always seemed to work best with the purple one. which i think is the next lightest to stock.

m71
What cam are you using?
-Kid

i have an 800dp on my 406 now, but about 5 yrs ago when i had the 3310 on my big block it had a Crane solid roller 260/270@.050 .663/.638 110*. don't remember off the top of my head what the advertised duration was. seems like it was 296/306, i'd have to dig out my spec card, if i can find it. :confused: