streetheatz28

I'm tired of saving money and have decided to go ahead with a cheaper engine build. Heres the plan...

350 bored .030 over - 355
Stock vortec heads .480 max lift assembled
stock crank/rods machine shop inspected
Sealed Power rebuild kit hypereutectic 9:73:1 comp w/64cc heads
Edelbrock RPM air-gap intake
Holley 650 DP mech secondaires
Hooker competition Headers
I'm looking at this cam:

Comp competition magnum hydraulic 230/230 duration 480/480 lift 2000-6000 rpm

What do yall think and what kinda hp should I expect? I will have a turbo 350 w/ a 2500 rpm stall, 373 gears mostly street use.

I also have a buddy that has a set of gm #462 castings that have been checked and cleaned up by a machine shop and have a mild port job for $150 they are complete and he says they will take up to a 500 lift cam would they be worth it for my goals or stick with the vortecs?

327???

stick with the vortecs, they flow much better.

that engine should put you deep into the 13's.

WheelsUp84z

iTrader: (2)

personally i wouldnt go with a .480 lift cam when the spring max is .480, either upgrade the heads for bigger springs or go smaller on the cam, otherwise im guessing you're going to have some valvetrain problem. the stock cam in the 350 HO crate engines makes 330 HP, and if you do a little port work yourself and an rpm airgap intake and i'd say you be almost 300+ at the wheels. and will put you in the 13's MAYBE high 12's

Sonix

iTrader: (1)

Yea, don't choose a cam based on heads limits, just fix the limits, then pick the right cam.
I'd use a split pattern cam on vortecs, they don't have a great exhaust side.

Damon

I agree- I wouldn't push the heads to their limits like that. The slightly smaller 270 Magnum might be a better choice with a little less duration (224*/224*) and .470" valve lift on both sides. I say this also becuase of the modest 2500 stall. I think the 280 Magnum might be a little "soft" on the launch with only 2500 stall.

If you want a split duration cam (probably a good idea with the Vortecs) you might look at the Comp XE268. It's 224*/230* with valve lift right around .470 on both sides using 1.5 rockers. That's about the biggest cam I've regularly heard having success on a dead-stock Vortec head. Beyond that almost everyone has done the usual modifications for higher lift and more aggressive valve springs.

streetheatz28

After alot of thinking I believe i'm going to go with the vortec heads "for high lift cams" they accomodate for up to .550 lift. I'll probrobly go with a .504/.525 lift 233/241 dur. its a lunati voodoo cam i'll also upgrade to a 3k stall. Would a 650 DP be big enough for this setup? After thinking about it it would be stupid to spend money on a slower setup when I can spend $300 more for something that will be alot faster.

Blake

iTrader: (2)

when i worked at a speed shop we started to grind downt he valve spring seat to accomidate larger diamter springs. easy as pie!!!!

however after the first one, we measured the rest of the stock heights and it had something like .610" of clearance from retainer to valve guide. minus .100" for saftey. gave us .510"

the springs are what restrict you on stock vortecs. I slapped a set of comp 981 springs, no mods, no nothing.

i installed a comp XE 274 cam into the motor with a .490 lift

i've done a 12.92 in myu 1980 malibu. stock bottom end, air gap intake and 650 demon carb with 3000 stall and 3.73's

60 ft of 1.9

could probalby run a 12.7 with traction