[sambo]

I put a couple of "good running" small blocks into some old Holdens back in the day - sourced cheap from a local wrecker who imported them from the States. They had a simple engine stand/dolly on the floor that they bolted the block to, a small fuel tank and a set of headers attached. Before handing my money over I used to run the engine for a short while (without cooling system) to check for any major problems.

Since you will have everything out of the car for the rotisserie job, would it be practical to make something similar and just run it briefly every month or so?