# 068 cam/rocker stud question



## wytnyt (May 17, 2008)

i have stock bottlenck screw in studs and need to replace them with straight 7/16" studs and polylocks.
i see several sizes available but am not sure the correct fit used with an 068 cam
can anyone tell me the part or size or where i can buy these at?
thx for any help


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## Rukee (Feb 8, 2007)

The stock screw in stud should work with your poly locks and roller tip or full roller rocker arms. They better, I just ordered a set of 1.65 ratio roller tip rocker arms. The sales guy at Jeg's said they were a drop in unit no MODs needed, come with their own poly lock nuts.


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## wytnyt (May 17, 2008)

Rukee said:


> The stock screw in stud should work with your poly locks and roller tip or full roller rocker arms. They better, I just ordered a set of 1.65 ratio roller tip rocker arms. The sales guy at Jeg's said they were a drop in unit no MODs needed, come with their own poly lock nuts.


ive had several tell me that they will work but will fail prematurely due to the bottleneck design of the stud.
they said i need to go to big block chevy studs but im finding several sizes..
i may try as a short term using polylocks but need to find a slim type polylock.
btw,,,know where i can find divider plates at rather than repops?
got my motor sitting waiting to be put together

oh just noticed ,,im using the stock rockers,,your rollers may be a different story i dont know


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## wytnyt (May 17, 2008)

what does 1.65 ratio refer to ?
im a little peeved at you rukee
you got me thinking of getting roller rockers now:lol:
how long before yours is up and running?,,,ill use you as a Guinea pig:lol::lol::lol:


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## Rukee (Feb 8, 2007)

Normal ratio is 1.5 to 1. For ever 1" the push rod goes, it pushes the valve open 1.5". A 1.65 ratio will open the valve 1.65" which gives a performance advantage over the stock ratio.
I wouldn't go with full roller rockers on the street. For the race car they are awesome. But for dependability on the street I prefer the magnum steel rocker with the roller tip. I'll have my set on Tuesday, along with some new outer carb base`s and the correct booster fitting for my new power brakes.


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## wytnyt (May 17, 2008)

the magnums look good but wonder if polylocks work with them,,,i dont trust just using locknuts

also,,rukee whats the stock length of the pushrods?
9.25?


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## canamjohn (Apr 9, 2005)

*Studs*

Just use 1970 454 Big Block chevy studs and the stock locking nuts. Will work just fine for your needs. To much fancy stuff is just more problems. to adjust the valves just turn the lock nut 1/4 to 1/2 turn past zero lash.


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## geeteeohguy (Feb 2, 2008)

Check out Jim Hand's articles about setting up a valvetrain on a Pontiac. They are on-line, excellent, and easy to follow. I ended up using ARP 7/16 studs that are straight and Pontiac specific that I got from Jegs when I converted the press-in studs on my #15 heads to screw in. I am not uning poly-locks, just the standard lock nuts. I have always used poly locks previously with the bottle-neck studs. An 068 cam is a stock Pontiac cam, and should work just fine with a baic stock set up. If you go to 1.65 ration rockers, you will need taller valve covers and longer pushrods, etc. I've always run 1.5 rockers, but then again, I'm a "stock" type of guy. for Horsepower, you want a big roller cam, lots of compression, lots of valve lift, and roller rockers. Another option that seems to work really well on Pontiacs is Rhoades lifters. They allow a high lift cam to work well on the street by bleeding down at low rpm. They are a little noisy, but the car runs well right off idle with no loss of low end torque, no washing the cylinders with raw fuel, etc. When the RPM's come up, the lifters "pump up", and utilize the cam's full lift. Good luck.
Jeff


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## Rukee (Feb 8, 2007)

Steel roller tipped 1.65 ratio rocker arms will fit under a stock valve cover and uses the stock push rods. The extended ratio is on the valve spring side, so it pushes the valve down further. It doesn't stand any higher then a stock rocker arm. As far as I know anyway, I'll let you know for sure tomorrow.


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## geeteeohguy (Feb 2, 2008)

I never ran them because of clearance problems a friend had. He had to remove the splash baffles inside the valve covers to make them work. I always thought the pushrods were longer, but I don't know for sure. Let us know, and let us know if there's any difference in the power. You're running a 389, aren't you? What heads are you running? My '65 has the stock (closed chamber/small valve) heads........I was thinking of some aluminum KRE's or Edelbrocks in the future if I feel rich............
Jeff


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## Rukee (Feb 8, 2007)

I think some aluminum full roller rockers might be too big for the stock valve cover, but these are the same stamped steel style as stock. Yes a 389, stock high compression heads.


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## Rukee (Feb 8, 2007)

Well, good news, bad news. The rockers fit under the stock valve cover, they are no higher then the stock rocker arm.
However, on my heads they move the push rod closer to the valve making them rub on the head causing binding. They have to come off, they won't work without ob-longing the push rod holes in the heads.

*EDIT*
I'm going to need some head work done anyway, I've never done anything with them and the car tends to puff some smoke restarting hot, so it's going to need some guides, I'll just have the pushrod holes drilled out larger and install the 1.65 ratio rockers when I put it back together after the valve/guide work. :cheers


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## geeteeohguy (Feb 2, 2008)

Rukee, you just shook a cobweb loose in my brain somewhere. I remember reading about the problem you're having. I Think the solution was oblonging the holes, being careful not to cul into the water jacket. Also, I think there are guideplates available to keep the pushrods in line when you're using 1.65's with pre-'67 heads. Maybe Wallace Racing? I can't remember.......good luck.
Jeff


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