Lifter block screws

[Andygears]

I am considering using later lifter blocks on my '50 EL right case. I bought, at a swap meet of course, a very nice set of cast iron lifter blocks from a shovel with solid lifters that fit well and rollers and all seem excellent. The aluminum blocks have cracked screw holes and ground smooth areas on the lifter support areas.

I want to cut countersink angles into the iron blocks and paint them silver and run the new set of lifter screws I also picked up cheap with the small hex heads. The package of screws provides the shakepruf lock washers.

My question is "Who knows definitely what angle the blocks have cut for the screw heads?" The screws appear to have a 82 degree included angle. Also should I run the lock washers? It makes some sense to run the lock washers on the cast iron but what is the logic of running lock washers on the aluminum blocks that will surely dig in and gouge the aluminum?
Any thoughts appreciated.

[58flh]

Andygears----If you look closely the countersink Might be a radious???--& no washers Just Anti-Sieze on the hex-screws.So look closely/unless shovel Iron blocks are reg Countersink.Im just thinking you may have dropped a screw in one & realized something was not in all the way.------Respectfully----Richie

[thebeast]

Andygears
The guides used in the early pans ,48-52,where made of aluminum and did use the shake proof washers.
I use the washers on my 49 with a dab of never - seize. While chasing a leak,I had one of the guides off several times and didn't see a problem with the washers gouging the holes, although I did replace the washers each time for reassembly.
James

[old.wrench]

andy,
The tappet blocks you have are probably later shovel if the don't have the countersinks for the screws. The earlier shovel blocks are countersunk just like the panhead lifter blocks. Instead of countersinking your blocks, you can buy flat bottomed 1/4"-24 screws from Colony. The simple solution .

I don't have any proof to back it up, but I wonder if the MofoCo eliminated the countersink because it was a weak point?? I've seen plenty of tappet blocks that had cracked or broken corners right through the countersink.

Geo.