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#1 |
Project 7dos
Join Date: Aug 2001
Location: Abilene, Texas
Posts: 876
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Vortec Head Question???!!!!
Can anyone tell me what the biggest cam you can run in the vortec heads. I have a 350 w/vortec heads and my cam recently went flat and i am replacing it...Can someone do some research(I wouldn't know the 1st place to start looking). I have a .454 lift in it right now and i have heard you can go bigger...
Thanks Jason
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7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290 |
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#2 |
My other Love
Join Date: Aug 2001
Location: Castlegar B.C. Canada
Posts: 4,085
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why do cams go flat? do the lifters hang up?
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![]() Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life |
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#3 |
Senior Member
![]() Join Date: Jan 2001
Location: Orem, Utah
Posts: 7,921
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The factory specs for the vortec say .5 inch lift max with the stock springs.
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I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson |
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#4 |
Senior Member
Join Date: Dec 2001
Location: Redding,CA...USA
Posts: 4,736
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this gets a little quirky...most publications say dont go over .460 lift...then ever one says the 350 ramjet has .480 lift with vortecs. Then I read never go over .450 ever(with out the spring upgrade). My suggestion...go with the spring upgrade to be safe.
Jim
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#5 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Having never read any GM papers on them, I am going by what all the magazines say...
.480 due to the lighter spring pressure. |
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#6 |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,403
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I dont believe you can run that much lift with stock springs on the vortecs.......I think it was in the .460-.470 range.
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#7 |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,403
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Scoggin-dickey has som info, If i can get the page up.... it sounds like to about .450 lift. http://www.sdpc2000.com/cart.asp?act...art&catid=2172
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#8 |
14.1 @ 96MPH
Join Date: Jul 2001
Location: Mesa, AZ
Posts: 2,811
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I'd say whatever cam they spec in the RamJet is probably as big as you can get. The 350HO 330hp engine uses one in the low .450's...
FWIW, messing around with Desktop Dyno, the Comp Cams XE256H seemed to work really well. WIIIIDE torque curve, and lots of it.
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#9 |
Registered User
Join Date: Dec 1999
Location: Old Mission, MI, USA
Posts: 2,510
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It's easy enough to check for coil bind when you assemble the engine. I have heard it is close to .500.
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Tim |
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#10 | |
Cantankerous Geezer
Join Date: Aug 2002
Location: Bel Aire, KS
Posts: 6,264
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Quote:
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Fred There is no such thing as too much cam...just not enough engine. ![]() |
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#11 |
Registered User
Join Date: Oct 2002
Location: Go to the middle of no-where then go another 25 miles East.
Posts: 8
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If you run more than a 465 lift you need to have the heads machined for clearance on the valve guides. It runs about 25 bucks a head to do this to. Scogin sells a set of heads that already have the machining done for an aditional charge, I am not sure but I think they run about 30 bucks more than the standard ones.
John
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Life begins at 100 miles per hour, then just keeps getting better and better the more you mash the gas..... |
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#12 |
Registered User
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 21,980
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I believe the RamJet cam spec's are .431/.451. You prob could run up to .470 lift max but the real question would be how long will the stock springs last w/more lift than the factory intended. The LT4 valvespring upgrade is good insurance & they have passed GM's 300 hr. full throttle test so they should last 100k in your motor.
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