Hmmm... the usual progression: Plenum goes, throwing oil through the combustion chamber at the catalytic converter; catalytic converter fails, causing heating of the rear-most cylinders and especially #8; excessive combustion chamber temperature causes cracks between the valve seats of #8.

Before you buy lots of parts, get that head looked at.

 

Also ran the engine in the driveway at 2000 rpms for about 10-15 mins to check for leaks. No leaks at all.....

 

hmmmmm that does make sense, but would i be burning oil at the rate of half a quart per 150 miles?

 

Possibly. It's something that deserves investigation if/when you take the truck down for repair.

 

especially after i just did the valve seals?

 

Just did the wet test on #8, i did another dry test first and it was up to 100 psi, and the wet test only barely brought it up to 105, so it cant be the rings! idk what is cuasing this any more, im soo lost!

 

wonder if you heads are creaked

 

These heads like to crack between the valve seats. I really don't see how that would cause excessive oil consumption...... new valve seals should deal with anything down the guides, and there isn't any any lower than that.... A bad head gasket that made it to the oil drain back holes would show itself in other ways as well......

100 pounds compression is the minimum spec though...... doing a leak down test would help find where the compression is going. (given your wet test results..... valve seats seem pretty likely......)

Clean the engine off REALLY well, and put some UV dye in the oil. Drive it for a few days, and then have a look. If you are leaking it out, that should show it. If it isn't leaking out, re-inspect your plenum.

 

Hmmm, alright thanks guys! Ill try to get a hold of some dye, and test that one out! I may pull the heads off soon to see if their cracked but i guess that dosent really explain where the oil is going!

 

does your motor, leak oil?

see mine leaked when driving,, i would drive home park the truck, 10min later nice size pool of oil,,, sit over night start it up, move it 20 feet park it no oil leak

what happen was the the vavle cover was lose, oil would work it way down after driving awhile,,,

but any way 105 not the best, sum people say restore engine additive works great for get compission back up,, but im not a fan of additives