I've removed the reservoir, water pump, heat exchanger, oil cooler, and a couple of pipes, from my 4-108. After internal cleaning I am now painting them using Depco engine paint and primer. I was using a Ford blue, but just bought a GM color that is similar to the Perkins blue.
The reservoir and heat exchanger just got engine paint, the Ford blue.
The oil cooler and pump have been primed and will get the GM Blue engine paint in a few days.
I spent a day last weekend attending to the block - much easier to get to w/all that other stuff off. Cleaned it and scraped all loose, flaking paint off and began using a rust-off treatment in areas. Need another day of prep on the block. I'm not going to paint the whole thing. Just touch ups here and there. Too cold to do more. But I can keep areas warm with heat lamps.