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Vortec head/ cam help

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Old Mar 12, 2007 | 10:10 PM
  #1  
specvgini's Avatar
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From: webster
Car: 1991 Formula
Engine: 5.7
Transmission: 700R4
Vortec head/ cam help

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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Old Mar 12, 2007 | 10:17 PM
  #2  
xpndbl3's Avatar
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
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.
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Old Mar 13, 2007 | 12:20 AM
  #3  
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From: Calgary, AB, Canada
Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
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.
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Old Mar 13, 2007 | 10:43 AM
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From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
If you'd stop buying and reading those hot rod mags,you'd have the time and money to set yours up properly the first time.
Just kidding ya......

Most vortecs are good for a .465" valve lift. You may find a few that are good to .480"

Of the ones I have checked, .454" was the lift limit.

So, you need to pop a retainer off and check yours.

In order to recommend a cam for your motor need to know a lot more about how you'll be using it.
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Old Mar 13, 2007 | 11:22 AM
  #5  
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Is this going to be your set-up?
1991 Formula(350 L98)
flowmaster catback
Edelbrock RPM performer intake
650 Quadrajet
Long tube headers


If so, there is no RPM spreadbore intake for Vortec heads.

As F-BIRD'88 said, need to know more about your intended use.
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Old Mar 13, 2007 | 01:13 PM
  #6  
specvgini's Avatar
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From: webster
Car: 1991 Formula
Engine: 5.7
Transmission: 700R4
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?
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Old Mar 13, 2007 | 01:48 PM
  #7  
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From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
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.
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Old Mar 13, 2007 | 01:51 PM
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
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.

You might also want to look at www.sdpc2000.com for their upgraded Vortec kit. Includes heads good to .575" lift, http://www.sdparts.com/product/SD806...merIntake.aspx has a Vortec Performer intake, http://www.sdparts.com/product/SD806...RPMAirGap.aspx has an RPM Air Gap (if you aren't going to stay with the q-jet - which probably is capable of flowing more like 750 CFM).
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Old Mar 13, 2007 | 03:21 PM
  #9  
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
how fast do you want to go with this motor?

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
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Old Mar 13, 2007 | 06:18 PM
  #10  
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From: webster
Car: 1991 Formula
Engine: 5.7
Transmission: 700R4
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.

Last edited by specvgini; Mar 13, 2007 at 06:25 PM.
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Old Mar 13, 2007 | 07:38 PM
  #11  
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From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
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.

http://www.converter.com/
http://www.converter.cc/

Last edited by F-BIRD'88; Mar 13, 2007 at 07:43 PM.
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Old Mar 14, 2007 | 06:43 AM
  #12  
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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

Last edited by Andy316; Mar 14, 2007 at 07:42 AM.
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Old Mar 14, 2007 | 10:59 PM
  #13  
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From: Lake of the Ozarks, MO
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.
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