Hey guys,

Doing the XR720HR cam swap, wondering if I can expect any valve cover clearance problems with the Comp 1.72 Ratio Roller tip rockers? Cam swap went well with excelent power gains, swapping to a stronger rocker for peace of mind with the heavy pressures on the beehive springs. Track numbers after retune on October 2nd, expecting 14.teens or so.

Thanks for the space and any info on rocker clearance would be great!

-Ryan

 

While I don't have an 8.1, on my 5.3 I was told to run my 1.75 Comp rockers, I'd have to knock down the casting bumps on backside of valve covers. I'd than have to remove the oil splashback baffles, which supposely some have had issues w/. oil in PCV by doing that. Which may necessitate a catch can, but IDK. I don't really want to do that, nor do I want potential PCV contamination. This guy said he didn't have that problem at all.

Also, another option for me would be to add a spacer, since the rails are so tall on LS motors, leaks wouldn't be a problem. Then, u need longer bolts too. This method will cost more, so I think I'll do the more labor intensive version. Not sure yet, & I gotta see if those spacers are as much as I remember.

That help?

 

Tho not 8.1 specific it cant hurt! Im doing a 6.0 turbo now too so I can apply your input on that one!

 

I can't take all the credit, just passin on what I recently learned. I was up late doin my springs, so I slept after work today. Had I not, I woulda called Comp to ask if there was anything special I need(ed) to know on these rockers.

So, tomorrow I'll call Comp to ask a few questions on my rockers. I almsot thought of not running the Comps cause of the labor to make em work, but I can't return em. The oil splashback is all that concerns me really. I figure i'll clean w. brake clean (which I wish there was a better option on an EFI ride).
I'd hope it would dry fast, which it does, but I don't want any brakeclean residue anywhere I don't need.

 

well the 8.1 valve covers are the shallowest of the bbc, but the heads have a taller cast in volve cover gasket rail. You could put earlier 502 valve covers on but then you need to make a new coil mounting. there is one cylinder on each head that one rocker is really close to the bolt and usually causes interfernce.

I have an 8.1 in a 1500

 

I have 1.7 roller rockers from raylar on my 8.1 and have no issues with clearance raylar also sells 1.8 roller rockers as well so I don't think you will have any issues.

 

Thanks for the replies guys, As soon as the correct rocker studs show up ill have it back together!

 

Doing the XR720HR cam swap,

Do you mean the XR270HR cam? ive never seen the 720

 

720 means the valve stays open all the time

 

Sorry about the typo! XR270HR!