On my motor (both builds) i could never figure out the valve train geometry using the 'mid lift' method. I spent days on my first motor trying to figure it out. The problem i kept seeing was that i needed a push rod so long that it would push the rocker way up the rocker stud. It would push it so high up the stud that i needed at least a .5" longer stud (probably longer). The end result was me using the marker method and adjusting my adjustable push rod until i get the rocker tip centered and as small as possible. I can see the wear pattern on the exhaust valve tips and it's centered on the valve tip and probably 1/3 as wide as the tip.
I decided that i'm going to order pushrods with oil restrictors built into them to see if that fixes my oil pressure issues on a hard pass. Since i'm going to be ordering new push rods i figured i might as well give the valve geo another try. I pulled the valve springs on #1 and put in dummys and away i went. With my current push rod length at midlift the angle of the rockers trunnions (sp?) to the valve is way off. I'm talking enough that i could fit my finger between the valve shaft and angle tool. The thing is though my max valve lift is only .002 off from what the card says. I then take my adjustable push rod and pull it out a bunch, i get the angle closer but the rocker is way up the stud and also my gross valve lift is now .040 higher than what the card reads. If i remember correctly from previous threads on this that shouldn't matter? the important part is the geometry right?
My real question is, for a Mark4 BBC with 990 heads, morel solid lifters, and scorpion roller rockers how long of a push rod will i probably need (just to compare), and is it normal for the rocker to have to sit so high up the rocker stud to get the geometry right? It seams like i would be putting alot more stress on that rocker stud.
** note, i did the mid lift method on my buddys 468 with 048 heads, scorpion rockers, morel lifters and i was able to figure it out no problem. He did end up needing longer exhaust rocker studs through. I dont see how i could be messing this up, it's not that complicated, least so it seams.