Your not required to put the manifold back on for this, just the head pushrods and rockers. your just looking for wide variance in testing. be sure to take out your fuel pump and ignition relays for this test.

What I mean is because there wont be a closed throttle plate the test will show ALOT higher numbers all you want to confirm is your numbers are within 15-20 percent of each other, be sure your battery maintains a decent charge because that will skew the test.

One more note, I had a hard time with a Powerstroke recently, I replaced the heads, gaskets, injectors, the high pressure oil pump just to discover the root cause was a warped deck (the mating surface of the head on the block. Which was not repairable and meant replacing the engine with a short block from the factory. On another job I was working on a forklift with a Chevy V6 LPG, it had overheated, classic scenario the computer reduces power up to 60 percent but allows continued operation until 255 degrees, which it hit. The heads had "lifted" which basically means the bolts stretched and it torched the head gaskets, all cylinders low compression except for #6, thought for sure it was the heads, replaced the heads, gaskets, rear main (started leaking likely because of overheat fatigue) I also replaced the intake and exhaust gaskets, the rad hoses and the heater hose for the LPG regulator. I didn't even second guess the heads being warped. Now I had an S10 for a friend who wanted to port his own heads, so I gave him those as spares to practice on, long story short I found out he ported them at his house and INSTALLED them on his truck, which evidently worked fine, I was sure the heads need at least major work. So try it, see what happens, worst case your out a set of heads.

 

well i took the heads to have them checked out. they said both heads are cracked. that sucks!
I bit the bullet and ordered the heads from clear water and they arrived yesterday, so it looks like ill be reinstalling them over this weekend. I baught the head gasket set that in cludes all the gaskete for the topend, new head bolts,new plug wires and plugs. so lets get started and hope i dont mess this up.

 

Dang buddy! that truck didn't cut you a break...both heads are cracked. WOW. Were you hard on the engine?

 

Interesting read guys, I had phoned 3 machine shops and all three had told me to not even bother bringing in the old heads as every magnum head they tested was cracked! Suggested to use new ones only.

 

well got both heads back on last night and all the pushrods and rocker arms back on . today will get the rest back together.
Is there any thing that I should know ,do, or consider before I try to fire it up? Any tips and or advice will be appreciated. I sure hope it fires up and runs normal. Need to get my son back on the road!

 

Make sure it has oil, and coolant. Prime the fuel pump once or twice before you actually crank the engine. Let fuel pressure build up, so when you turn the key, it will fire right up. (hopefully)

 

Ok well here is the best and the worst of it. We got every thing back together, drained the oil and put some new oil to clean out the milkshake, pulled an all nighter. turned the key and it fired right up! That was the good of it. after it fired up it seemed to be running alittle rough, thought maybe a vacume leak problem, because i had broken a couple of the hard plastic lines, got them repaired but no change.let it run for a few minutes pulled the dip stick and there was milk shake, and oil was blowing out of the dipstick tube. I shut it down ,drained the oil and changed the oil filter, fired it back up let it run for a minute ,pulled the dip stick and the oil was clear,but still blowing out the dipstick tubeand still idleing a little rough, when poof a flame broke out right behind the engine! Got the flame out right away, let the thing cool down. fould fuel leaking down behind the engine dripping on the ground. searched and searched and finally found that an injecter at the rear on driver side was leaking. pulled the fuel rail off and discovered that the top O ring had a scar or nick in it. replaced the O ring and put it back together, turned the key on and checked for leaks. No leaks, so I fired it back up and let it run for a few minnuts. Checked the oil and the oil is clear., but still blowing out of the dipstick tube, Still idleing a little rough and seems to inch up to running a little warm, but not sure. Also it is blowing preasure with smoke out of the tube that comes from the fitting on the passenger side valve cover to the breather. is this a pcv valve? I changed the PCV on the driver side, but no change.
WHY IS OIL BLOWING OUT THE DIPSTICK TUBE, WHY IS IT STILL RUNNING WARM, WHY IS IT RUNNING ROUGH?
Any suggestions as to what to check for would be appreciated.

 

I was hoping this would be a top end issue only, sounds to me like your son has some explaining to do.

What that is your experiencing is severe blowby, from destroyed rings most likely.

 

Run another compression test.