Prozone heads any good?

[zrocket]

Hi i am new here I bought a used 1995 6.5 l drw 3500 silverado 4:10 rear end crew cab with a cracked head.The engine was replaced in 2003 with a 2000 replacement engine 80,000 miles and now a cracked head. I was wondering if anyone here has any information on Prozone heads ebay. thanks Ron.

[Robyn]

First off

Welcome to TDP :D:):D:

The only aftermarket heads I have had any experience with are the ones from Clearwater Cyl head.

Used a set on a personal rig, and have had others I know use them.

Loads of crap out there, so be careful

Frito lay was using the Clearwater heads for a long time.
They bought them by the pallet load instead of rebuilding the high mile stuff.

Mine served me for 50k miles and I sold the rig and it ran well.

The other heads I have had experience with are genuine AM General parts

$1000 a set

The aftermarket stuff is gonna be a China casting and from there ?????

Good luck

Missy

[zrocket]

Thanks for your response these prozone heads have a diamond stamped prechamber cap. And i was under the impression that those were good improved heads?

[Robyn]

With any aftermarket head the markings are of ?????? value

The Diamond is the standard mark for precups used on a turbo engine.
The diamond cups have the large fire port.

Missy

[zrocket]

Thanks the existing precups from the head i took off has a dot.

[Robyn]

The 2000 engine should have a diamond on the cups.

You do not want mismatched heads, so I advised yanking the other side to see whats there.

The heads need to match, or there can be consequences down the line.

Mismatched cups can cause different power pulses on the cylinders that result in stresses in the crank that you don't want.

Keep us in the loop

Robyn

[zrocket]

block cast numbers that i used for I D f280 behind cyl # 8 12555506 back of valley at the fire wall no 506 diamond in valley.

[Robyn]

Gm block

[zrocket]

IYHO ... should i just do a low ball fix on this block as far as used heads ect...or spend for top notch replacement heads....I dont have any exp with these blocks/heads. Thanks and i do appreciate honest experienced answers i take no offense to experienced advise.

[john8662]

where is your crack on the head? was it using water because of the crank or because of a blown head gasket? These heads crack anyways, many don't leak water. cracks between the valves is normal. Depends on how wide the crack is. Usually it's a fracture, not a cavern.

[Robyn]

One area that MUST be examined is the area on the block deck where the gasket fire ring sits.

This is very important on the 4 end cylinders.

If there is a noticeable erosion of block material near the water passage on #1 and # 2 (Front cyls) where the fire ring sits it can be trouble.

The two front water passages in the heads hold coolant in contact with the deck surface and over time cause electrolysis to take place and the deck will errode and there can be a low area where this happens.

A dark stain will NOT hurt anything, but if there is a groove where the gasket ring sat that can be felt then there is a good chance that a new gasket will fail as well in short order.

Cleaning the deck real well is imperative.

With the engine in the rig the best way to clean the deck is to use a small grinder with a fine bristle wire brush, and go over the entire area well to remove every trace of old gasket and crud.

Stuff the lifter case area with rags to keep junk out.

Before installing the new gaskets be sure to wipe the surfaces with a clean towel soaked in brakekleen or similar solvent to remove any oil.

Clean all head bolt holes with a proper metric tap
Holes must be clean and dry. (Squirt with brakekleen and blow dry)

ALWAYS USE A NEW SET OF TTY HEAD BOLTS.

THIS IS A MUST DO AS THESE ARE A ONE TIME USE BOLT.

The bolt kits come with torque pattern and specs

IIRC
IT'S 22LBS THROUGH, THEN 55 POUNDS THROUGH AND THEN 1/4 TURN MORE THROUGH.

Every time you torque, is through the pattern by the spec sheet sequence.

DO NOT ADD ANY SEALERS OR OIL TO THREADS.
The bolts come with an Orange dry Silicone sealer on the threads.

Felpro gaskets are the best choice.
Felpro also offers the TTY bolts (Torque to yield)

Missy

[zrocket]

after cleaning the head i spotted the crack i thought it shouldve been more noticeable without cleaning also some of the gasket material was worn through when holding up to the light i could see through it but no major blow out like the fire ring. it was the second cylinder in from the right #6 i believe. there was pressure in the water reservoir no water in the oil white smoke out of the exhaust it would clear up and start again on and off im sure i had a faint diesel smell from the water tank. other than that it ran like a clock when not stumbling from the water....temps fluctuated.

[zrocket]

I will be doing a thorough cleaning of the deck and head im just going to put it back together with new gasket and bolts....if it works fine if not i will tackle it in the summer months its outside in Portland Oregon id rather seal it up from the winter weather who knows maybe i get lucky with no leak. i will post either way good or bad...thanks for all the helpful input.

[zrocket]

Installing a new head gasket fel-pro 9701 pt........unto the right side of my 6.5l t.d. i was under the impression that the blue stripes faced up to the cylinder head surface....neither of the gaskets i have will line up on the right side for the stripes to be up ...only on the left side will that work (drivers side)..is that normal ? thanks.

[zrocket]

Interesting crack in right side head at the valve traveling a 1/4 inch up towards the intake manifold ...With the head off ..I put my finger in the water jacket and did not feel a crack with my finger nail on the inside...So i cleaned the inside with break cleaner at the spot where the crack would be if it went through ...Then I applied a thin layer of heat resistant J.B. weld at that spot and replaced the head gasket thanks for your help and advice about these heads cracking and not always leaking...No smoke after a 40 mile run at various speeds up to 70 mph and matting it climbing hills........95 drw c.c. 6.5l 60,000 on replaced engine. not lucky enough to score the amg but for $2700 shes clean and strong.

[zrocket]

Also on the combustion side of the head a made up a thin batch of J.B. weld and rubbed it over the crack left it raised a little let it set for a bit then tapped the J.B. lightly with a hammer to fill any part of the crack that the J.B. could enter and scrapped the excess off...I really couldnt tell if any filled the crack or not it was so thin of a crack.:D:o