........Never bought a rebuilt engine, but those I've done I'd coat the cam with EP moly grease, and then pre-oil using my granfather's old Milwaukee 1/2" drill motor driving the oil pump, until I had a good flow at the lifters.
Since it was all Ford and Chevy stuff, getting junkyard valve covers was no problem and these had a window cut down the center for rocker arm adjustments. After the distributer was put in I'd turn the electric fuel pump on to fill the carb.
Crank it up and run it at 1500-2000 rpms to keep the oil pressure up for 10-15 minutes. I used a 20wt oil. During this time the rockers were adjusted, and the radiator was topped and capped, and the valve covers replaced. Then it was take it out and drive it for awile with some moderate acceleration from stops, and a 10-15 minute trip on the freeway. After that it was drain the oil and replace it and the filter. I would watch my P's & Q's with it for 500 miles or so.
I guess it was in the early 80's I had a magazine with several articles in it and one featured the big Caddie engines in pickup for tow duties. Since they were designed to haul around big luxury automobiles, which was more or less cruising operations, they werent' really designed for performance. Mainly they loafed through life.
The article dealt with performance operations you could do or have done. Since ALL engine blocks are basicly the same thing (pumps), the performance aspect for any of'em comes from the heads. Naturally also parts associated with the head, ie: cam, intake-exhaust, and valves.
There was information of mods to the stock heads, and also oiling improvements. However there was a company that specialized in performance parts for the Caddie and Lincoln engines. I thought big block Ford parts were expensive
! I suppose the crowd doing these mods was very limited, but you could sure get some impressive HP and torque numbers from those big cube gas engines.
They featured a highrise aluminum intake manifold that looked about as big as my porch as one of their performance mods. It retailed a bit over $400 at the time.
Rick