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I need some help picking out parts for my setup. i have a freshly rebuilt 350 and i believe it's .40 over. i'm firm on running the vortec heads, and for a little while i'd run them stock. from what i've read on here in stock form make lift is 480. so what cam setup do i run? plus should i just run a cam package that includes springs and lifters? if i upgrade the springs i've heard i could run a larger cam.. pointing me in the right direction.. also what rocker arms would be good cause won't that raise the lift too? so i'd have to be conservative do to the heads limitations. eventually i'm gonna get work done on the heads so i can run a bigger cam, but right now i'm pressed on time and cash so i'm gonna have to run the stock vortecs. so again what cam and lifters?
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__________________ 1991 Formula -14.2@97 mph
Current mods: rebuilt 350 .030 over, edelbrock performer rpm intake manifold, edelbrock performer 4brl 750cfm carb, edelbrock intake filter, slp 1 3/4 headers and y pipe, flowmaster american thunder catback, holley FPR, holley external fuel pump, MSD 8.5mm wires, all new brakes, KYB GR2 shocks, lakewood lower control arms, new kickdown cable,new throttle cable, and B&M shift improvement kit.
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lift is usually limited to .450 on most of those heads. Go get them machined for screw-in studs, bigger spring pockets, and cut down the valve guide then pick out the proper cam like a XE274 and only build it once right.
if your heads aren't bolted on yet, spend the $100 and machine 'em for bigger lift springs. It's so easy and cheap, it wouldn't make any sense to under-cam it based on a simple mod. Silly, just plain silly.
oh no thats what i'm running currently. however the motors blown so i'm dropping in a freshly rebuilt 355. since i started this thread yesterday i actually found a set of vortec heads on summit for 776. and they are premachined for the different studs and have the larger springs. it states they can hold up to a .550 lift cam. so with that said i'm definately gonna spend the extra 100 for those and just run a bigger cam. my next question is how much do rocker arms raise lift? lets say i have a cam with .510 lift and i use 1.6 rockers, what would that make the lift then?
You can easily calculate that your self. You don't need our help.
We're here to (and don't mind taking the time to) give you good advice, but, are not here to hold your hand.
Use a calculator and figure it out yourself.
Do not get all hung up with valve lift. The duration and LSA of a cam has much more to do with how it will run (RPM range) and how much power it will make.
You still have not given any details trans, converter stall, rear gear, intake manifold etc on your car and what you are after.
0.510" is the lift at the valve, typically expressed with stock rocker arm ratio. So, 0.510"/1.5 times 1.6 would be the lift. Or, 1.6/1.5=1.067, times the lift.
my buddies motor would go high 12's in my car and its just a stock vortec headed, LT1 cam, some edelbrock vortec intake, and a 750 double pumper. it went 13.5 in his 83 chevy truck with a 3500stall/3.73 gear. thing is as fast as my L98 camaro and i'm down probly 80hp or so
sorry i didn't give you all my setup i just didn't want to write a long reply. the shell is a 1991 formula. the tranny is bone stock right now and the rear end is 3.23 i believe. the setup i'm aiming to build is a 355 sbc,performer rpm air gap intake manifold, as for the carb i'm still undecided. the carb i currently have is all screwed up so thats going out. right now i'm focusing on the motor and getting it in the car. in the future i'll rebuild the tranny with a shift kit and i'll get a higher stall. i'm low on cash so i don't have money to build a well rounded setup such as motor,tranny, rear end. i'm fairly new to small blocks so thats why i'm asking questions that some may feel are stupid. your help is greatly appreciated. the heads i have picked out our vortec heads for high lift cams nal-vorteczz5 from summit. specs are: clearanced for .550 gross lift, 7/16 studs same intake and exhaust valves as the normal heads, but the springs are larger 1.379.
as far as what i'm expecting to put down or run, i'm hoping to run deep in the 12's once the tranny is worked on. i originally was planning on dropping in the gm 350 ho crate engine, but then this fresh motor fell in my lap. with the bigger cam and little bigger displacement i hope to make well over 330 thats advertised for the crate motor.
For a flat tappet hyd cam I would use a Comp XE-262H10 (12-238-2) or a Crane Powermax H278-2 #113801
if you want a hyd roller cam pick one with the same .050" duration and simular LSA. Such as the GM LT4 hot cam.
All these will run well with a stock converter and 3.23's and better when you step up to a new high stall converter.
A 3000 stall custom 245MM converter that retains the internal lock up clutch would be just right.
you could buy the LS1/6 springs (beehive), they fit with no mod. to the heads at all and allow just over .550 lift cam. (with 1.5 rockers self align.) You will also need the retainers and locks to go with them. Thats if you want to go that way. If not, then i wouldnt worry about a cam too much because the vortec heads stock are designed to handle mild economy cams. .450-.475 max. Another good thing about those beehive springs is that they are lighter than say a upgraded dual spring on modded vortec heads (85g vs 143g) which gives you more valve control at higher RPMs. These springs are more expensive than regular dual springs but now you dont have to have to pay someone to machine those heads for you. Just slap the dang springs on there and grab a cam. Im done talking now.
Spring # 26915 or 2918 (both can handle same lift for vortecs)
retainer # 774
locks/keepers # 648
I am running the GMPP vortec zz5 heads from summit with a 355 block, Holley vortec Steath Ram, lt4 hot cam, 1.6 rockers, 3.73 gears, pro built 700 r4 with a edge 3000 stall, Hedman long tubes with summit mufflers. Engine dynoed 390hp at the crank would probably get 330 rwhp, plenty fast for cruising the streets. The only work I had to do to the heads was drill the pushrod slots bigger to accomadate the 1.6 rockers. I would highly recommend these heads as I've used them in many marine applications also running low 400hp motors at 5200 rpm for hundreds of hours and no problems.
