What you just described is exactly what I am worried about, so I am going to put off the head gasket as long as possible. For one thing, the project cash aquifer took a big hit on the bearings, and needs time to recharge. For another, my Father and Uncle/Cousin, who are both mechanics who used to drive this truck, think it is stuck valves from all the rust. If procrastination mechanics causes the compression to magically heal, all the better for me. Hopefully the motor will limp along well enough for me to fix the rest of the systems, if not, we have flagged a backup motor that is in a 60's boom truck.
People keep trying to talk me into a big motor. There are 454's all over this county, and there is a CAT diesel with an Allison in the hay barn. Not sure it would fit, but.... I have no intention of ever selling the truck, so there is no potential future value in keeping it original, but I am romantically attached to the idea of keeping the original motor running. For one, I have a LOT of rust scraping, knuckles bleeding, eyes watering hours into it. For another, Grandpa wants to go for a drive in it as is, and talks often about how they used to braise a baffle in the manifold for a cool sound. What may end up happening is that when I do pull the motor for a rebuild, I will "hot rod" it. Who knows, all pie in the sky fantasy at this point. For now I have races to bang out of the hub and a gas tank to mount. We will see what the next week brings.
I'm enjoying the ride as you sort out the issues 20 years of sitting in weeds can cause. It does sound like the parade truck is well on it's way to being a driver. For some reason I'm also reminded of the "Whole Earth Catalog" from my misspent youth.
added in edit: It occurs to me you're at the edge of the WIIT (While I'm In There) rabbit hole. It does sound like a head gasket is called for. Not a big deal usually. But then with the head off it's fairly easy to drop the pan... pull the rod caps... push the piston/rod assembly out the top of the block (after knocking the ring ridge out of the top of the cylinders)... replace rings, deglaze the cylinder walls with a hone or just sandpaper... reinstall with new rod bearings and do a cheap inframe ring job.
But wait, WIIT why not just go ahead and pull the main caps and work new main bearings in over the crank, replacing in the cap.
But wait, might as well just pull the engine and since it's only a 6 cylinder have it bored, new pistons, hot tank the block, get the head rebuilt, new cam bearings, new water pump and oil pump.....WIIT
Good Luck!
Ron
