Got ya, thanks.
I've used a Bridgeport many times, no longer available to me though.
I can see that fixturing would be a challenge as well.

Cutting the stands in the heads would be rather permanent.

Ron

 

Always had to grind those tabs off to use stock rockers on trick flows so I assumed they would be okay on stock heads without the tabs too, because the rocker bolts still technically locate them.. Thoughts?



I see you're thinking in that but it wouldn't work because if you drop down the rear side of the rocker it comes off the valve tip.. you still have to set preload with the rocker touching the valve tip which keeps the rocker arm in the same place at rest that it was with the stock cam. Dropping down the rocker stand height is the only thing that would do what you're picturing. What you're picturing is the rocker arm sitting lower down at the contact point of the rocker to pushrod, but if you only do that then the rocker tip will no longer be in contact with the valve tip.

 

You are correct. Doh!

 

Happens to the best of us man, lol

 

I did did call them and they told me .690 lift was no problem with the shaft rockers.
I have a set on the bench now waiting to go in. I ran my new motor on the chassis dyno with a 654 lift cam and stock rockers. I am gonna take a look to see if there is any wear and swap out to the BSR rockers. But I can tell you the stock rockers showed no sign of slowing down at 7500.

 

What PRC Cathedrals the 247s?

 

Odd they can claim 690 is no problem, while using the same geometry and rocker that, from what lots have said, causes problems at 620+

Not trying to be negative here, just doesn't smell right and.... **** I don't know, I'd just say look at the rocker wipe real close before running it hard.

There was a dude here recently and I wish I could remember the thread. He had I believe 610 lift on one set of lobes and 630 on the others. The valves that had 610 lift looked great and the valves that had 630 had galled up tips.

 

They are they 237 I think, sucks getting old I cant remember if they were the 247 or the 237. I had the local super stock guy go thru them and help them out a little. It put down 550 on motor and 700 on 100 shot with a high stall. I dont take to much stock in a chassis dyno with a high stall its more of a tuning aid.
I was told from Comp the cathedrals have the best geometry for rocker stability. for the LS3 and LS7 guys the lift standards may be different.

 

I made 610 wheel with 247s, hyd roller 416ci .

 

Been racing the BSR rockers all year. Best pass so far has been 9.3 at 140 MPH. They seems to be holding up very well. Sees 7200 every pass and a few 7500 when it gets turned up a little.

 

That sounds impressive