I`m the middle of laying carpet amd I packed up my repair manual so I can not look up compression specs.

I check the compression when it was cold both cylinders were 122psi. Is that in spec for a 96 ext580.

Thank in advance.

Peter

i believe most compression's on the sleds is 150 brand new . but i am not positive

That is a good reading for that sled. You have to remember too, all gauges will read differently. As long as both Cylinders were the same or very close, you will be ok!