Figured I would update. Barring the myrid of problems with the brake system (different topic) everything has gone mostly smoothly. Yanked the motor and trans in late Feb. and upon pulling the head, found a .020-.030 wear ring on every cylinder. This wasn't a case of stuck rings, this old girl was just worn out. Definitely a 200k+ mile motor. Broke her done, dropped her off at the engine shop with all the 50-60 year old guys who know these motors, left instructions for what I was wanting, and focused back on brakes and electrical.
A month later and the engine is back. Punched .040 over, new RV cam, head machined for better squish, HD valves, and new from the ground up. Couldn't find the original color paint, so just went with DD Alpine Blue to match the truck. The block had a slight crack between cylinder 2-3 on the cooling sleeve that had seeped water at one time and caused some rust. Given that we drained full coolant during engine pull, I assumed that she was run hot and hard one day which caused it, seeped water, and then the block effectively self sealed. The builder patched it and put a block of sealer in the engine as well.
My questions for those of you more well versed in these puppy's: - What additional care do I need to take for the block? Given that the truck will see more use in the winter (upper midwest winters) is it viable to run block heaters to prewarm the engine prior to starting to lessen thermal shock to the block? - The builder did not use hardened valve seats. I spoke to him about it and he explained that the hardened valve seats really come into play with higher RPM setups and excess time spent at the higher end. Given that the engine is a low RPM grunter in a big truck, the hardened seats aren't necessary. I heeded his advice as he has been building these suckers for nearly 50 years. Should I be worried? Is there additional additives/steps to take for care for non-hardened valve seats? - I have zinc additive for the oil to break in the new cam. Beyond that, is anything else advised? - I asked the builder and he indicated that conventional oil is best for these engines. With a rebuild, are the factory weights still advisable or is a different weight more modern oil best? I had 5w30 in her for cold weather but then swapped to SAE40. Should I stick with SAE40 even with cold weather?
I appreciate and input and advice as I continue to learn these trucks. I am still awaiting trans (figured she should be freshened up since shes out) and then HEI and a number of small parts, and then she is going back together, hopefully soon given the excessive time I now have due to COVID-19. Looking forward to getting this girl back on the road.
