Well, you have to get the valves working correctly to get compression, so the first thing is to get them sorted out. Replace any parts that are not correct. YOu can figure that out by comparing the bad ones to the others that are working correctly. Once you get all the valves sorted you should be getting more like 130 psi on the compression I would think.

It sounds like the porr engine has not been cared for....but it may still respond to some tlc.

Those 280es are really really tough engines.

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.