just did a quick wet test with wd-40. 4 of the cylinders almost doubled, 4 stayed mostly the same, those were paired cylinders. 1&2 and 7&8. So I'm thinking bad head gaskets and worn rings. I have seen the truck run. It is propane only fueled. And also the timing chain and gears are good.
compression wet and cold was:
1. 15
2. 15
3. 90
4. 110
5. 80
6. 85
7. 30
8. 30
I'm pulling the motor for a rebuild.
Thanks for you reply
007BRONCO