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With the stock B-body cam, probably 10 hp or less.
With the F-body LT1 cam, guys have claimed more. Also keep in mind the intake port flow on our iron heads is slightly better than on the aluminum heads.

The stock heads on our cars are good. They'll easily support 400 hp with a cam change.
 

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Just what I suspected. Not worth the effort. Thank you.
Exactly.

Stock heads with performance cam > Stock cam with ported heads.

KW
 

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Dan, put down the crack pipe!
Don't mislead this guy.
Whatever you're doing to convince yourself that old stock springs are good to 5500, this guy is NOT going to do that. He's probably more normal than that!
 

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Dan, put down the crack pipe!
Don't mislead this guy.
Whatever you're doing to convince yourself that old stock springs are good to 5500, this guy is NOT going to do that. He's probably more normal than that!
Pat...
Mine go well above 5500rpm with a quarter turn from zero lash.
And on my 210000 mile SSuperwagon engine.
If you want to over rev for absolute last tenth in the traps, Install Springs..
But not worth time or money and will work just fine for 95% of what he is doing.
Way too much work for too little improvement.

Time management ..get a cam and matching spring kit.
Far more rewarding and ROI!

D
 

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.....But not worth time or money and will work just fine for 95% of what he is doing.......
And what about the other 5%?

You'd really advise the guy to 'take a chance' like that?

Really?


And FWIW.....I do agree that a mild performance cam would be a good thing. But swapping the old stock springs with a rocker ratio upgrade is a 'no-brainer'.....at least to me.

KW
 

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Pat...
Mine go well above 5500rpm with a quarter turn from zero lash.
And on my 210000 mile SSuperwagon engine.
If you want to over rev for absolute last tenth in the traps, Install Springs..
But not worth time or money and will work just fine for 95% of what he is doing.
Way too much work for too little improvement.

Time management ..get a cam and matching spring kit.
Far more rewarding and ROI!

D

I don't know about that Dan. I run 340 lbs on the seat and would run more if the lifters would stand it. Some of our brethern run as much as 550 lbs on the seat. Valve spring pressure is what controls the valve and keeps it where it's supposed to be when it's supposed to be there. There is definitely HP and ET in controlling the valves. Indeed, the HP is made and controlled, or not controlled, in the heads and valvetrain.
 

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I don't know about that Dan. I run 340 lbs on the seat and would run more if the lifters would stand it. Some of our brethern run as much as 550 lbs on the seat. Valve spring pressure is what controls the valve and keeps it where it's supposed to be when it's supposed to be there. There is definitely HP and ET in controlling the valves. Indeed, the HP is made and controlled, or not controlled, in the heads and valvetrain.
On a STOCK CAM?? Jeeezzee !!
Hey guys ..been playing with Spring Pressures for Decades.
The 1969 Z28 used Stock Springs 84# Seat/206 Open and Ran 7400rpm. My 64SS 327/250 Stocker 1973 would go across the traps at 6500rpm.
All we did was Zero Lash them. That was all we could do by the rules.

Changing Springs for very limited results. Guys I have better things to do that spend 2 hours changing springs.

My 95SS Pure Stocker can only use Stock Springs. Same factory stock springs. Does have Blueprinted Cam yet gone through the traps at 6500rpm with no problem.

Having extra Spring Rate not going to hurt. Too much you will wreck your lifters. The Flat Tappet guys have to use expensive hardened everything to turn 8000rpm.

We have mostly NA Street Engines. Reliability is far more important to me that power for a Street Car. Like good smooth power but no need to twist a Stock Cam even with RR more than 5700rpm when you are well past the power curve at 5400rpm and TQ is 1000rpm less. Got the Dyno Curves to prove it.
 

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Ever checked any used stock springs? I have a valve spring checker in my shop and can tell you that I have. They're usually around 50 lbs at 1.700" on the seat and not much more at open pressure. Just imagine how much more control you have with a set Crane H11 springs with 130 or so lbs on the seat. Even a stock cam will love you :)
 

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Ever checked any used stock springs? I have a valve spring checker in my shop and can tell you that I have. They're usually around 50 lbs at 1.700" on the seat and not much more at open pressure. Just imagine how much more control you have with a set Crane H11 springs with 130 or so lbs on the seat. Even a stock cam will love you :)
Yes I do check the Springs. Have to in Stock. Have to be on Spec.
Whatever mine are at they are working fine.
When the 95SS ran HOBO installed new LT1 replacements rated 110lbs seat.
Did not see any ET improvement that was attributed to them.

Last season before surgery added Damper Springs to the Stock Springs on the 95SS Pure Stocker. No improvement.

D
 

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I don't know about that Dan. I run 340 lbs on the seat and would run more if the lifters would stand it.
Stock style lifters wont take more than 340 lbs open pressure?
 

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Merry Christmas, Dan!
I hope Santa brings you some valve springs.....maybe you can go out and set a record then :D
 

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Discussion Starter · #19 ·

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