Are these compression numbers OK?
 

140 on five cylinders, 150 on the 6th. Is this OK? What is the acceptable range?

How is a 6 - 8% leak down test on all cylinders. Is that OK?

don't know about leak down but your compression numbers are just fine. They should be within 10%

Both are good.

On a leakdown, ideal is less than 5%, over 5% and something is showing some wear.

I was just about to edit my response when Kurt logged in. 5% or less is best. How many miles on the engine? If you have 100k or more, I think 5-8% is to be expected.

ICD,

Where are you located? Altitude makes a large difference in compression measurement.

Kurt, Tim, and Paul are right on.

Everyone should record these measurements on a regular basis for a baseline for your engine. How do you know you have, or are developing, a problem if you don’t know the history?

Best,
Grady

The car in question is an '87 Carrera. The car is in Kansas City. It has 115k on it., but it had a valve job around 55K.

The bottom line question is this:

Will this car need valves or rings any time soon with these test results?

No guarantees, but probably no.