Will a roller cam make "oem" jetting way off on a Holley 3310?
5,7 / 350 roller cam, ported heads intake (1500-5500) headers 5speed
I "need" a good power making jetting advise, newer mind the mpg
jets power valwe sec.spring

 

The fact that its a roller cam VS flat tappet will make no difference to the carb - it will never know the difference. The cam specs, however, can make a very big difference to the carb.

What are the specs of the cam you want to use? What are the specs of the rest of the motor? I used a Holley 3310 for a long time on the 350 I used to have before I sold that engine to put the big block in - excellent carb, I should never have let it go!

 

Comp cams CCA-08-422-8.

Cam Style Hydraulic roller tappet
Basic Operating RPM Range 1,600-5,400
Intake Duration at 050 inch Lift 218
Exhaust Duration at 050 inch Lift 224
Duration at 050 inch Lift 218 int./224 exh.
Advertised Intake Duration 270
Advertised Exhaust Duration 276
Advertised Duration 270 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.495 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.502 in.
Valve Lift with Factory Rocker Arm Ratio 0.495 int./0.502 exh.
Lobe Separation (degrees) 110

 

10.3:1 comp. ported heads, (flow enough to produce +450hp sad the guy that flow tested them after i was donne. if this combo makes 350hp i'm glad -400hp i'm thrilled) intake same rpm as camchaft, headders.
any other info needed that i left out?

 

You'll have to fine tune it yourself, but I'd start with 71 front jets and 76 or 78 rear jets as a baseline. Powervalve - you'll need a vacuum guage to figure out which one you need.

 

jepp, I know i have to fine tune it... (each engine is unique)
sec. spring oem to soft or what to expect?

 

Expect better results if you use one of these: http://www.summitracing.com/search/?...0housing&dds=1

A 5-speed should have a double pumper carb, not vacuum secondary.

 

That carb should be good right out of the box

 

its all trial and error.. anyone can guess a jet size but it varies according to the engine and how far you are from sea level.. just to many variables to guess

 

It will be reasonably close out of the box, in that it should start and run ok, but as with any engine it could be put on, it will need some tuning to get it just right. There is no universal calibration that works with every combo out there.

Thats also assuming the carb is actually new and coming out of a box. Those carbs have been made for over 45 years, so there are lots of used ones out there as well, all with different calibrations on them.

 

Better choice of words on your end youre right.
Once he drives it he will have to figure what it needs, if any.

Looking back many yrs had a combo similar to his same carb tried a 750 DP also. Didnt know much on tuning...car ran great except for a slight flat spot off idle....a slightly bigger squirter woulda cured it but ignorance is bliss...ah, bigger pumps jets power valves, etc. Basically the car never ran right after that and fouled plugs LOL

OP keep us posted, sure someone will guide you in the right direction should it not be spot on.

Ditto on DP litle more gearbox friendly...if you DO have the VS theres always a quick change kit for the springs IF it even needs it. VS carbs are nice and smooth Ill give it that much, nice to drive