I have a 85 305. I put a .512 and after a while it pulled the rocker arm studs, which I new it was going to, but what would be the biggest I could get that woundn't do that? Around .488?

 

as a rule i figure .460 to .475 is about it. i always change springs and go with screw in studs when i go with a bigger cam. also trash the factory rotator and retainer assembly and go with aftermarket retainers.

------------------
ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

So EDE,
So would I go about getting screw in studs? I mean, how would I put them in? Thanks.

------------------
1984 Firebird SE
1985 Camaro z28 305 engine T-5 Five Speed Tranny Performer Intake, Accel Distributor, Raceing Starter, 650 CFM Carb, .488 Lift Cam, Dual Exhaust.
92 Camaro Leather Seats Console, carpet everything. Soon to put in 700R4 and 427CI. (Hopefully)

 

easy, you just tap the holes that the stock studs are pressed into, and buy rocker studs that are threaded.

 

You won't be able to use stock rocker arms either. The slot isn't long enough and will bind. You either need some long slot stamped steel rockers or some roller rockers. As mentioned before, change the valve springs. Stock springs are very weak and probably worn out anyway. They also start to get very close to binding above .480 lift.

Screw in studs are really only required when you start running higher spring pressure. I think you have an interferance problem pulling the studs out.

Stock valvetrain is just that. Stock. As soon as you change something like a cam, the rest of the valvetrain should be upgraded to match the change.

------------------
Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block (times are for the current engine)

Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586

Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

The ZZ4 crate engine does .510 lift with stock stamped steel rocker arms.... it's possible that old style NSA stamped steel rockers don't have long enough slots, but all newer self aligning stamped steel rocker arms will take at least as much as .510 lift from what I have read with no worries of binding in the slot.

I'm planning on running the GMPP stamed steel rocker arms from the ZZ4 on my comp XE284 383 temporarily.