I have a 1985 Aspencade that has high compression 195psi in one cylinder, low compression 150psi in one cylinder and normal compression in the other 2 cylinders. I found a 1985 LTD motor that I can get for a very reasonable price. I do not know what the differences are between the motors. Can I swap these motors easily? I was given a price of $3500 to rebuild my motor. Is that reasonable?