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Will this cam work for my stock vortec 062 springs??

9K views 18 replies 9 participants last post by  spinn 
#1 ·
Hey All,

I've decided not to machined down my guides and purchase this GM roller cam with a 431/451 lift. Would I be in trouble if I ran with this cam along with my stock vortec springs. This is pretty much the only performance change with my 98 vortec roller block. All else is stock.. the block is std. bore with stock dish pistons. What do you guys think? Here is the GM cam from summit:
http://www.summitracing.com/parts/NAL-14097395/
:boxing:
 
#3 ·
That Cam was used in the RamJet350, HT383 and Marine Vortec crate engines.
The RamJet used 1.6 rockers for .460" IN, .481" EX lift , HT383 used 1.5 rockers.
Stock Vortec springs only have about 70# @ 1.70" seat pressure. I agree ^^^ an upgrade is needed. I'd check with a few Cam Co.'s to see what they recommend.

GM used a very mild spring upgrade.
Spring = #10212811
Retainer= #10241744
These had 80# seat @1.70", 256# rate still pretty weak.
 
#4 ·
I used that cam in my vortec truck for the last year with factory springs. Ran fine! Made a nice little improvement. Your not going to set the world on fire, but does make a bit of difference. If you get it I think it may be cheaper through www.gmpartsdirect.com!
 
#6 ·
How did you all break in your cam? Did you use weak springs.. and then changed to your new set? I was advised to break in my cam with a set of weak springs. The problem is that I don't have the tools to change my springs after I break in my cam. I would have my guides machined down with the new springs put on. Still confused about the whole spring change. What would cause the issue of my using the stock vortec springs with a true 450 lift? :pain:
 
#9 ·
redfish211 said:
How did you all break in your cam? Did you use weak springs.. and then changed to your new set? I was advised to break in my cam with a set of weak springs. The problem is that I don't have the tools to change my springs after I break in my cam.
That isn't necessary- the springs that should be used w/that cam aren't so stiff that weaker break-in springs are needed at all. Besides, the cam is a roller, therefore doesn't require a traditional break in like a flat tappet cam has to go through.

I would have my guides machined down with the new springs put on. Still confused about the whole spring change. What would cause the issue of my using the stock vortec springs with a true 450 lift? :pain:
Ever hear of doing what's referred to as a "ghetto grind"? More on mods to the Vortec heads is HERE.

The problem I see w/using used OEM Vortec springs, is they're even weaker than when first installed. The stock Vortec springs are spec'ed for a cam w/an intake lift of 0.414" and an exhaust lift of 0.428" and a low redline RPM.

Instead, you can use a set of the "Z-28/LT-1" springs and your stock retainers- springs are about $30/set.
 
#10 ·
cobalt327 said:
That isn't necessary- the springs that should be used w/that cam aren't so stiff that weaker break-in springs are needed at all. Besides, the cam is a roller, therefore doesn't require a traditional break in like a flat tappet cam has to go through.

Ever hear of doing what's referred to as a "ghetto grind"? More on mods to the Vortec heads is HERE.

The problem I see w/using used OEM Vortec springs, is they're even weaker than when first installed. The stock Vortec springs are spec'ed for a cam w/an intake lift of 0.414" and an exhaust lift of 0.428" and a low redline RPM.

Instead, you can use a set of the "Z-28/LT-1" springs and your stock retainers- springs are about $30/set.
I've heard about the Z-28 springs. I've checked out Scoggin Dickey and the carry them. So I can use my stock retainers..what about the locks? My machine shop said they would machine the guides and install the springs for about 75 bucks. I have no skills machining anything..and I wouldnt wanna damage my good heads. Also..is SDPC the only place that sells the Z-28/LT-1 springs? Didnt see them on Summit.
 
#13 ·
$75.00 is not a bad price for the machine work if they have to disasemble and cut the boses down and install the springs. They can cut the bosses down in less than 1/2 hour. You can buy the springs for $32.00 a set. The number on them is 943X and you can use the Vortec retainers.
 
#14 ·
My 305 has 3100v6 springs and retainers on the vortec heads. Umbrella seals along with the beehive springs had lift clearance till past .480" . My 305 used the Edelbrock Performer cam . That was the largest cam that confidently fit the stock guide about .440" of lift.

The salvage part numbers were 10166344 and 343 , were the retainers and springs. At 1.8" IH the valve had 98 lbs seat pressure. At .450 the open pressure was over 280 lbs.

http://www.hotrodders.com/forum/attachment.php?attachmentid=50898
 
#16 ·
quicksilver67 said:
I'll tell you from experience, you need to get the heads worked on. The Vortec heads will not accept a cam with more than 400 lift. After several broken springs and pushrods I found an article on Super Chevy that explained my problem. Heads must be worked on.
Sorry quicksilver, but you might want to read that Not-so-Super Chevy article again! Most vortec heads are good for .420-.460 lift! The Vortec's I had on my truck varried between .450-.465 stock. I ran the exact cam in my truck, with factory (very) tired valve springs for a year with no problems! Is it best to run factory springs on these heads in factory form? Probably not. Is it possible? Yes. You just have to check your retainer to seal clearance!
 
#19 ·
My 305 has vortec heads with 1.94 valves. Told that would not fit.
Vortec heads with unbrella seals and LS6 valve springs allow about .470" of lift. Currently my build uses the performer cam .420/.442 lift. No problems relating to valve lift. Drill pushrod holes to 3/8".

 
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