Can anyone tell me from experience whether the new Yella rockers will clear 98 perimeter style valve covers without grinding the covers? The folks at New Era told me that they haven't had any complaints, but that isn't the answer I need. If they do clear, I'll order a set and then sell my old style Yellas (which require grinding) which are unused/virgin.

 

i'm interested in this also

 

onebadZ28...I have an email in to Yella Terra (Australia +14 hours).
I'll post their answer early Monday.

 

Good deal i'm looking forward to their reply

 

Curious here too

 

Ya, sorry. All the 98 cars (shop side) builds with them, have been to center bolts. I cant recall any sticking with there heads.

 

Thanks, I appreciate the clarification.

 

Update to original question...it has been a futile experience at connecting with a human being either by email or phone with Yella Terra in Australia.
I was assured that a reply will be coming from a gent at Yella in MI/USA.
Keep you posted...
Glenn

 

I'm becoming a little irritated here..just typed a long paragraph, then accidentally erased it.
Oooooo-k! The VP in charge of marketing for Yella/USA replied. He said that "the new rockers will fit under stock covers". However, now I'm not sure that he is aware that 1998 covers differ from 1999 & up. So, I've emailed him again just to make sure.
Meanwhile, representative from Yella sales in Australia emailed me saying that the new ultralights "should fit". "Should" doesn't cut the mustard!
Have you ever wanted a product really bad but you just can't seem to convey the issue and receive an exact answer?
Anyway, please stand by....

 

Here's the latest...after receiving questionable answers from the reps in Australia and the US, I emailed them once again restating the issue (difference) between 1998, then 1999 and up. At that, their reply was.."we don't know if they'll fit because (A) in Australia we don't have those type of heads, and (B) in America we can't say that the new rockers have ever been mounted on 1998 style heads". I was sure that the rep in the US called the Aussie rep. Thanks to both for their prompt replies. So, I figured it was best to drop that avenue and then to move on.
I then took out my trusty 806 home-ported heads (now I have alot of elbow grease invested in them+valve job+cleaning-can't give 'em up). I started reviewing the original problem which is that the old style rockers will not clear the bolt area on the valvecover. Just to make sure, I mounted a set of "old" Yellas to make sure that they'll clear by height. With the gaskets installed, and valves completely shut, the highest-most part at the tip cleared the cover by approx. 1/16". Good so far. Next, I tried to match the bolt holes, and sure enough, there is a clearance problem between the rear of each rocker and the bolt area on the cover. See Photo. Grinding the cover will leave very little room for error. Looks to me like grinding a bit too far will put a hole in the cover! If I DO have to grind, I believe I'd rather have the new Ultralites instead of the old style.
Here's the real question... Although the "old" and the "new" are the same total width, the shoulders of the "new" rocker appear to be wider than the "old" ones, which would mean that the "new" bodies are slimmer. If I measure the "old" body, side to side directly through the oiler hole (is that what they call it?), I come up with 15/16". Can anyone out there give me the same measurement on one of the "new" rockers? I'll bet it's smaller. So, here's the thing. Is there enough clearance "new" to fit without grinding? If not, (and I don't believe there is), the next option might be cover-spacers.
Finally, unless there is someone out there who can tell us that they indeed have successfully applied 1998 & the "new" style, it looks like we'll need a guinea pig. So, here I am! I'll be calling New Era to ask if I can buy a set with the idea that if they don't fit, that I'll be allowed to return them.
Stay tuned!

Glenn

credit to "somebody" for the photo