(This is the 396 in my '57, but I believe the principles will apply to SBC 3rd gens - or BBC 3rd gens for sure. . .)

I've been running Comp Magnum roller tip rockers for years, like since the engine was rebuilt in 1997. When I put in the XS282 solid lifter cam in '06, I was never very happy with the side-to-side slop, which made setting lash difficult at best. And, I suspect was leading to valve control issues. It would never rev anywhere near the advertised upper power band of the cam. I also seemed to have a steady diet of loosening problems with the stock-type locking adjusting nuts.

This winter I picked up a set of the Ultra Pro Magnum rockers, stock 1.7 ratio. I installed them this evening (first time I've ever messed with polylocks). Went much smoother than I expected. They are much more stable with the roller fulcrum, which made adjusting a lot easier and quicker, and even though I adjusted them cold, were much quieter when I started it up. I couldn't take it out to get it up to temp this evening (foot of snow last night), hope to be able to do that tomorrow (or at least let it run longer to get up to temp - it was getting pretty late by the time I fired it up this evening) and readjust them.

But, the really nice thing is they fit under stock height valve covers and don't interfere with baffles. Big plus in my book.

We'll see if it makes any difference in the way it runs. But, along with my other new toys, a hand-held practice tree (which revealed a very bad inconsistency problem) and an Innovate wide band O2 air/fuel gauge system (which showed a very poorly tuned carb), I'm getting pretty excited about the upcoming season. . .

 

The ultra pro magnums are what im considering putting in my 565. Full roller rockers are a nice addition to the valve trane.

 

We were scheduled to have a special test day at the track tomorrow, but it had to be postponed due to the snow storm we got this week. So, I'll have to wait at least a week to see if they make any difference.

Need to get back out to the garage now and see about taking it for another test drive.

...to get it warmed up and reset the lash, of course. . .

 

I heard about the snow you got. This time last year we got hit by a snow storm.

I've had Pro Magnums on my engine for many years. I won't even recommend aluminum rockers to anyone. For just a little more money you can put on the Pro Magnums and have a much better rocker.

Although there are some good rockers available, I feel the next step up from Pro Magnum rockers is a shaft rocker like Jesel or T&D. The Jesel street rockers are around $1000 and would still hold up to anything I could throw at them.

With aluminum heads, it's recommended to set the cold lash 0.006" tighter.

 

I just set them all at .016" for the initial adjustment. I haven't established the delta for cold vs. hot. Normally I set them I .016"/E .018" hot at high altitude. The cam card says .016" for both, but Comp recommended the looser exhaust to help out a little up here.

 

They fit under straight up stock valve covers? Or "stock height" as you said?

 

In my case, they are stock height but aftermarket aluminum covers.

 

It was about .002" due to being warmed up. Now I know.

 

Do you think that these "Ultra" Pro Magnums would be good for AFR 180 or 195s plus a comp cams XFI268? Trying to get an idea for some good street rockers.
Also, Do they even sell the regular "Pro Magnums"(non ultra) anymore? I can't seem to find them listed on their website and they are harder to find through suppliers.

 

I don't know why they wouldn't be good for that application.

It appears they are phasing out the Pro Magnums.