M1tch

I have a 350 .060 over flat top pistons, #906 vortecs, stock rods, federal crankshaft. I have the money now to invest in a cam, intake, and carb. The heads have the stock springs with a max lift of .450. So with a bigger cam will i just need to switch the springs? and what cam will give me damn near 400hp? what carb will be the best for my setup? should i use the edelbrock performer vortec?

Orr89RocZ

iTrader: (20)

i believe the heads are only good to .470 lift before the retainer on most spring setups will bottom out on the valve guide boss/valve seal. You'll have to check that measurement but thats the general concensus.

I hear beehive springs and retainers will drop right in on vortec heads and will be good to well over .500 lift. For a flat tappet cam tho, i think the spring pressures would be too much.

Else you will have to either have the machine shop grind down the bosses and install new seals so you can get more lift, or shim up the springs some and run offset locks.

By shimming the sprigns up around .050" and running .050" offset locks, you gain an extra .050" of lift, making .470 turn into more like .520"

If your going flat tappet cam, i'd try the xe268 from comp cams (or any similar duration specs cam, maybe try a hot voodoo cam from lunati) which should make near 400hp.

M1tch

whats the cheapest most efficient way to do it? How much would shimming down the springs cost? and if i did that do you still suggest that same cam? And what type of cam with shimming the springs?

This is my first engine build, my girlfriends father is an experienced engine builder and hes helping me do everything. I'm just on my own with finding the right combo, so anything to help me go forward with the process is appreciated, i do believe im on the right path so far lol :-/

five7kid

iTrader: (14)

Any competent machine shop should be able to cut the top of the valve guides so double springs will fit over them and the valve travel is increased. Comp cams will sell you the tool if you can't find a shop willing to do it.

Orr89RocZ

iTrader: (20)

shimming would be the cheapest way to do it but i'm not sure how much safe lift you'll end up getting.

Some say max lift on vortecs is only around .430 before valve retainer to guide seal clearance becomes a problem. ALot more say .460-.470"

if it is only .430, then shimming will only give about .470 lift max safely. If it is .460-.470" then shimming probly will give .500-.510 lift max safely.

its getting close at that point. You will have to take measurements on teh heads to verify what you have and what you can get out of them. I still like the cam choices i posted, however lift is getting close on the bigger cam at .490". the XE268 at .480 lift at its highest point would be a good match with comp 981 springs, .060 shims and .050" offset 10 degree locks and regular retainers

I think its better bet that you go get the heads machined down alittle and get screw in studs for safety

M1tch

I almost have everything together, what size hood will i need to cover the clearence with a edelbrock performer RPM and a carb? I was wanting to get an SS hood or just a 2" cowl. But since im painting on the heritage stripes im not sure how good that would look with an SS hood.

Current Parts

350 4 bolt .060 over ROLLER
Comp roller XR270 w/ hydraulic lifters
Edelbrock Performer RPM 7116
Vortec #906 heads
Federal Crankshaft
Federal Flat Top pistons
Stock 5.7" rods
Carb?????
Rockers????

Im paying this guy at a speed shop to build my differential and 700r4. Hes putting 3.73s in it and axels, aluminum driveshaft.

I'll have a $5000 loan cleared by the end of this week

$1000 for hood and stripes painted on
$1200 transmission/ b&m shifter
$1000? Differential
$500 miscellanious motor parts

$1300 for suspension/ brakes/ interior clean up ANY IDEAS?

I'll be posting pictures as soon as i put this baby together any suggestions would be appriciated!

Orr89RocZ

iTrader: (20)

check out the aniversary 02 SS camaros, they have stripes painted on with that hood to give you an idea. I think either hood would look great. I'm not sure you will need a hood anyway. It may clear the stocker. I'm not sure how tall the cleaner is above the manifold, but it may be like my HSR was, just barely clears

Differential rebuild? Just get a new aftermarket posi or a low mileage zexel torsen diff out of a WS6 or SS ls1 car. with gears and labor i dont think it will cost much more than 700-800 bucks to do. If you buy a good used torsen, it will be much cheaper.

sean86sc

the performer rpm will clear the stock hood if you use a drop base air cleaner