Just a note....testing the compression with the engine running does not really change the compression much. There is no combustion pressure because the compression tester is screwed in place of a plug and will not ignite the mixture.

I have done it before with the engine running and not and the difference is not noticable. Trying to test it with the engine running is not recommended though because of the danger of getting something caught in the fan belt.

At that mileage, the bottom end should be still in great condition if the car has had decent care. Your idea of running it to free stuck rings might work, but you should determine whether it is leaking into the exhaust manifold; an exhaust valve leak, the intake; an intake, or the crankcase; a ring leak. This can be done with a leakdown test, I believe.

Also be sure to get the correct, non resistor plugs for the car (I believe that model calls for them).

Good luck.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.