[RIDDLER]

Anyone using these in there pontiac? Any probs?

[RIDDLER]

Anyone using these in there pontiac? Any probs?

[Squidward]

My brother-in-law runs 1.7 BB chevy roller rockers in his 73 'bird with 428 c.i. The stud is the same size (7/16"), but I would guess the biggest concern is the geometry so that with a high lift the rocker tip doesn't crap out the edge of the valve stem. He hasn't had any problems for a few years except for wasting the trannys he hooks up to it and losing paint from body flex on hard launches.

"...ridge reamer and ring compressor? Do they have tools like that?"

[Marty Phipps]

When I had the Summit cam in my birds old 350, I was running B.B.C. 1.7 rockers without any problems whatsover..
When I tried them in my 428 though.
I went with a Comp Cams extreme energy series cam.

The .510 lift exhaust was too much, causing spring bind, and premature valve tip wear.
That only occured at high RPM'S
The .507 intake valves suffered no problems at all.
So I guess the extra .003" lift on the exhaust side was enough to cause problems
But other then that, no clearance problems, no need to elongate the push rod holes, etc.

[ponchopete]

The Chevy 1.6 ratio rocker arms will not give you proper valvetrain geometry. I know that Ford roller rockers, which are a 1.6 ratio, work well on the Pontiac, and rarely create geometry problems. I imagine that the Comp Magnum roller tip Ford rockers would work equally as well. The only issue with the Ford roller tip rockers is that they are designed exclusively for a 3/8" rocker stud, so, provided your heads are equipped with screw-in studs, you'd need to change to 3/8" studs. Small block Chevy studs would work fine. Of course, once you buy both the rockers and the studs, you've probably spent enough to just buy the full roller rockers.

"My car would be fast if it had an engine, transmission, and rear axle in it."

[SCOTT ESTERLE]

Ford rockers are available in 7/16 also.

[Skip Fix]

Ok guys here's the info on rockers. The BBC is about 0.120 longer stud to roller tip than any Pontiac rocker I have checked.No way they would set the roller tip correct on a Pontiac valve tip unless the pushrods are way short, then the geometry would be way off.

Comp's BBF ss rocker is just their BBC with the pivot drilled 0.045 offset.Be about 0.080 too long for a Poncho.

SBC 1.6 are way too short(have the specs somewhere). The Crower 1.6 Pontiac ss I got a few years ago said SBF on it and it was WAY too short also.

Now the Crower offset trunnion SBC have a longer length than a regular SBC, probably about the length of a Pontiac rocker.

If you are just a little off you can play with pushrod length or lash caps. Mid lift the rocker needs to be centered on the valve tip, there are other factors for "perfect" geometry in a rocker to be perpendicular to the valve also at a certain point in lift, mid to high depending onwho you talk to. That's why its not a straight line from the pushrod cup,pivot to roller tip. Many different rocker have different arches for this reason.Also have different diameter roller tips.

There is a gauge sold in the Natioanl Dragster for measuring the exact clearance of roller tip to valve stem center.

[tempest455]

Skip, I've been using SBF rockers for years. Never measured them but I did make sure I had the correct pushrod length.

The purple anodized rocker is the SBF 1.6. The other is a Crower, Pontiac 1.5.

http://www.wauknet.com/douthitt/images/rockers3.JPG

tempest455

[Skip Fix]

I've heard the Crower ss 1.6 Pontiacs are right on, but the one they sent me marked SBF was way short.

I'm trying to come up with a drop on 1.8 Pontiac rocker.