Hi all, The 413 had reason to kick my butt. I borrowed a real compression gauge today and did a compression test across the entire motor. I am somewhat discouraged. I had 3 cylinders I couldn't get my hand held compression gauge into, and 2 of them are a problem. I believe 80-90 psi should be enough to start a motor, might not run great, but should start.
Compression readings are as follows.
#1 70 psi
#3 70 psi
#5 30 psi (couldn't check that one)
#7 60 psi (couldn't check this one)

#2 75 psi
#4 90 psi
#6 90 psi
#8 90 psi (couldn't check this one)

I pulled the valve cover off the left head. It was nasty in there, big chunks of caked and crumbly stuff. All the rockers and valves were moving, but one valve on #6 was definitely not closing completely and one of the valves on #1 was hanging up (delay in closing) as the motor turned over. There was a lot of slop between the valve and the push rods on those 2 valves, the rest of the rockers seemed about normal.
At this point, we have to at least pull the driver side head, and as nasty as it was under the valve cover, the whole motor needs cleaned up. Its probably coming out. Gene