Crack in head, can it be reused.

[kennythewelder]

Sorry Kenny but NO you do not have to replace both heads as a set. The only wear on a head in normal use will be at the valve guides and the valve seats/faces. There are thousands of vehicles out there that have had one head replaced under warranty and there is no effect on performance.

Having said that, IF the heads were milled to flatten them then replacing both at the same time would be prudent.

Yes, I understand what your saying, and if you want to keep cost down to a min, then yes you can just replace one head, but, if you do, they both have to be re worked together, and that was my point. The heads need to match each other. You can not just re work one head, and not the other. That was what I meant. Sorry if my message dis not come across like that.

 

[Dd1994]

Yes, I understand what your saying, and if you want to keep cost down to a min, then yes you can just replace one head, but, if you do, they both have to be re worked together, and that was my point. The heads need to match each other. You can not just re work one head, and not the other. That was what I meant. Sorry if my message dis not come across like that.

I dont get why new heads would have better performance assuming they are the same casting and the old ones are fully cleaned, valves lapped etc. I dont really have the money for a set of performance heads right now. I think I will check the other head and then get a replacement head.

 

[kennythewelder]

So, here is the thing. As I said before, the original Vortec heads had thin castings. Most replacement heads will be a heaver, thicker casting. This is why I said to replace both heads, but I understand how it is to be on a budget. When it comes to replacing heads, or re working heads, some times in the end it cost as much to re work the old heads as it does to just replace them. I work in a machine shop ( not automotive) and our labor rate starts at $100 per hour. Some shops charge more. It doesnt take long for that to add up. A good set of cast iron performance Vortec heads are less than $1000. Ten hours of re work time and your at $1000. Plus there are the parts, valves, seats, valve guides ECT.. Then all you have at the end of the day is a set of thin cast OE Vortec heads. Maybe you will get lucky and get away spending only a few hundred bucks, maybe. I dont mean to sound negetive, I just want to give you insite in what I see people do everyday. I see it here is our shop all the time. People freak out when we quoit a job, or when they see there bill. Most of the time, they dont understand what it takes to get a job done rite.

 

[NightRunner]

Awh just a little JB Weld should see you right home!

Kidding, don't use the head. Summit has a decent cylinder head deal, last I checked was $350 each fully assembled if you have the money. If not, plenty of other Vortec's out there for the pickin'.

 

[94burbk1500]

Awh just a little JB Weld should see you right home!

Kidding, don't use the head. Summit has a decent cylinder head deal, last I checked was $350 each fully assembled if you have the money. If not, plenty of other Vortec's out there for the pickin'.

I'm more of a Flex Seal guy, myself.

 

[NightRunner]

I'm more of a Flex Seal guy, myself.

You must be registered for see images attach

 

[Dd1994]

So, here is the thing. As I said before, the original Vortec heads had thin castings. Most replacement heads will be a heaver, thicker casting. This is why I said to replace both heads, but I understand how it is to be on a budget. When it comes to replacing heads, or re working heads, some times in the end it cost as much to re work the old heads as it does to just replace them. I work in a machine shop ( not automotive) and our labor rate starts at $100 per hour. Some shops charge more. It doesnt take long for that to add up. A good set of cast iron performance Vortec heads are less than $1000. Ten hours of re work time and your at $1000. Plus there are the parts, valves, seats, valve guides ECT.. Then all you have at the end of the day is a set of thin cast OE Vortec heads. Maybe you will get lucky and get away spending only a few hundred bucks, maybe. I dont mean to sound negetive, I just want to give you insite in what I see people do everyday. I see it here is our shop all the time. People freak out when we quoit a job, or when they see there bill. Most of the time, they dont understand what it takes to get a job done rite.

Wasn't planning on taking it to a machine shop. I'm cleaning it myself and lapping the valves myself, and replacing the valve seals. I realize that's maybe not ideal but realistically with 280 000 km(180 000 miles), doesnt it make more sense to do that and get a bit more mileage out of it and then save up for a crate engine, instead of dropping a grand on new heads for an old motor.

 

[kennythewelder]

Wasn't planning on taking it to a machine shop. I'm cleaning it myself and lapping the valves myself, and replacing the valve seals. I realize that's maybe not ideal but realistically with 280 000 km(180 000 miles), doesnt it make more sense to do that and get a bit more mileage out of it and then save up for a crate engine, instead of dropping a grand on new heads for an old motor.

Got you.

 

[98 Nitro]

Wasn't planning on taking it to a machine shop. I'm cleaning it myself and lapping the valves myself, and replacing the valve seals. I realize that's maybe not ideal but realistically with 280 000 km(180 000 miles), doesnt it make more sense to do that and get a bit more mileage out of it and then save up for a crate engine, instead of dropping a grand on new heads for an old motor.

I agree with that. I wish GM still had their Vortec short block then you could say buy some aftermarket heads for now then if the old engine goes just buy the short block and add your heads.

 

[blackburb]

Wasn't planning on taking it to a machine shop. I'm cleaning it myself and lapping the valves myself, and replacing the valve seals. I realize that's maybe not ideal but realistically with 280 000 km(180 000 miles), doesnt it make more sense to do that and get a bit more mileage out of it and then save up for a crate engine, instead of dropping a grand on new heads for an old motor.

I was in your boat about ten years ago. Overheated my 97 Vortec and cracked both heads(cyl 5&6 between the valves IIRC) at 215k. Dealer wanted $1800 to replace the heads. I found a GM long block crate motor for $1600 shipped with the 3year warranty and installed it myself for ~$2000 including new distributor, tool rental and beer for my BIL for the weekend. Sounds like you are on a tight budget... I’d replace the cracked head and save up for a new crate engine. FWIW... and not a recommendation but I ran my motor with cracked heads for 3 months while I saved up to make repairs. Motor was way down on power very slow acceleration, would not climb a hill and throwing misfire codes but still ran down the highway at 80mph.