cracked head?

[Iron Weasel]

oh did the wet test just on #5 it went up to 95 but dropped after that to bout 75 what does that say and my battery went dead

That says that your piston rings are worn, but that's not really a big issue at this point. #5 has 34% less dry (21% less wet) compression than your highest cylinders and ideally there shouldn't be more than a 10% difference between the highest (#1 & #2) and the lowest (#5 & #6) cylinders.


Cylinder #1 - 100% of 120 PSI
Cylinder #2 - 100% of 120 PSI
Cylinder #3 - 91.6% of 120 PSI
Cylinder #4 - 91.6% of 120 PSI
Cylinder #5 - 66.6% of 120 PSI
Cylinder #6 - 83.3% of 120 PSI

Cylinders #3 & #4 are within 10% of each on cylinders #1 & #2, so that's normal. Cylinders 1 - 3 are on the passenger side while 4 - 6 are on the drivers side and since the lowest pressures are #5 & #6, here's my diagnosis:

Blown head gasket between cylinders #5 & #6.

Book time to R&R both head gaskets is 10.3 hours + 1.1 hour if you have air conditioning. Thankfully, the parts for it are actually pretty cheap. That being said, do yourself a favor and get your gaskets from Napa or from a Ford dealer...head gaskets are one area you don't want to be cheap on.

Also - GET NEW HEAD BOLTS!

I can't stress that enough. Head bolts are "torque-to-yield" which means they stretch out, so any time you remove the heads, you have to use new head bolts. There's a specific torque sequence and torque stepping for the head bolts and intake manifold that you need to follow, so you might want to rent a 1/2" torque wrench before you start tearing into it.

If you have any questions about how to do the job, lemme know and I'll get it to you.

 

[tuck817]

do i need to have the heads machined or just the head gasket replacement

 

[Iron Weasel]

At a minimum you should have them checked for flatness and cracks.
If they're slightly warped, they can usually be machined back to being flat, but it can raise the compression if you take too much off.