I am working on the heads, have problem with rocker arm supports. No Kiddin? Stripped treads on Rocker Roller Screws. Went to dealer had them order new Rocker Arm support. It matches what is in the service manual but not what's on the car. Removed it from car and found it was broken in 4 places. Part no 161~72. (Part broke in middle of part number) The one the dealer sold me and is pictured in Service manual is 351-1181 which looks like 4 upside-down u's. The one one the car has fewer holes(No decending arms with holes like 351-1181. In fact I cannot mount the 351-1181 because the lower holes are not on the block. The 161~72 in cast Aluminum but thicker/stiffer. The dealer had no listing for it.
Does anyone know about this part, the whole number, etc???????? Was there a rolling change that didn't make it into the manual? The car only has 26,000 miles and will run very well once I get this fixed.

 

Turns out that the 351-1181 will, in fact fit although the 4 screw holes in the little arms that hang down are not used because there are not any tapped holes in the block for them. The older part number was froma RWD HT4100 part(How'd it get on my FWD?) but the part was replaced by 351-1181 although the dealer does not have notations that they are interchangeable. Had to talk to a few mechanics and do more forum searching to get this info.

 

now, that is a low mileage ride.

thanks for posting the outcome.
that should help someone else someday.

i wonder what i would find there if i opened my
'88 H.O. 4100 Allanté special. she is got many
more miles than yours and gets pushed to
the RED zone often.

 

The big problem with the Support Brkt cracks in mine was that 2 were at Bolt holes one at the rocker roller. This caused one rocker roller to split, allowing one rocker to turn somewhat sideways allowing the push rod to hit the inside of the valve cover. consequently at least one valve was not opening and there was a lot of Clack-Clack noise. The dealer said to put some risolone in the oil and it would go away! I drove it like that a little while until another one went (Rolling rocker split and then It wouldn't run. The mechanics say to always do a whole new support arm and new rocker rollers when there is a problem. Don't try to go to a larger thread For a stripped hole, etc. Once you have a problem it just keeps getting worse unless you redo the whole rocker arm support assembly. It isn't that costly, just some time Car ran like new with the new assembly installed

 

just to gt some clarity .. the stripped hole was in the ....