Well, instead of wipping out my handy dandy 8mm drill bit and ream the guides that way, (I know it sound crude, but it has worked for me many times befor) I bought a 5/16" to 11/32" reamer from McMaster to do the job right:
Close up:
What I found is that guides reamed to the proper size feel looser than what I used to accept with the drill bit method. Probably because the finish is more uniform. I'm lucky that i didn't have a valve stick in the past.
I also double checked the possibility of drilling and tapping the top edge of the cam side to accept the earlier valve cover. IT IS POSSIBLE. But there is good news, and bad news.
I did crude checks in the past wit the G60 valve cover. There are allot of stiffening webs in the top of it that interfered with the stud bosses on the 1.9 cam towers. I dremeled out the interference points and low and behold, the stud holes in the corners line up, and they are also the right size for the tap!
So I drilled and tapped them all (No. 9 bit):
A DRILL PRESS IS MANDITORY. If you get a crooked hole, the valve cover ain't going over the studs.
And there is pleanty of web thickness to almost cover the whole thread insertion:
Now the bad news: The early steel valve covers won't work un modified:
The edge roll on the old steel cover interferes with the 1.9 straight gasket surface.
Allot of the edge roll has to be removed. Here is the gasket in the valve cover showing how much over hang there is;
Its not out of the question, but it has to be reduced significantly, probably to 1/2 the gasket thicness. I wonder what the right way to do this is?
The G60 valve cover, after a little dremel work, is a straight shot:
I also lapped all the valves. So hopefully next week end, I'll have fire in the hole....