I hope I can find some locally that are already built, and I think they are the good ones too.

 

If you're close to a machine shop, I'd just get the heads worked, you've already got a set, mill them .01 to clean them up, and if you've got the coin I'd go ahead and have them cnc'd for bigger valves. If you don't have the cash, I'd just fix what was broken if it's just a bad valve.

 

Beings new stock Vortec 350 heads are just a shade over $300 each complete, you need to be careful in how much work you allow a machine shop to invest in just freshening up a set. Yes, you could do minimum work to them and come out cheaper than what a pair of new heads would set you back, but if you did find that they need guide work and so on, you can easily surpass that, not to mention if one were to have a set cut for larger valves and minor porting. I believe if I were looking at having larger valves installed, I would at least take a look at the complete small port Vortec Bow-Tie heads; at a little over $500 each they are a little more than the large port variety, but would actually be a better fitment for an otherwise stock engine. The complete large port Vortec Bow-Tie heads, at around $490 each, will still have you investing over grand by the time your finished, but just like the small port versions, they are stronger than the factory castings, flow better and still cheaper than some of the alternatives. I would probably go ahead and go for the large port set if I had plans for future upgrades. If I didn’t, I would just pick up a stock replacement set and continue to enjoy life.

 

there should be plenty of decent used heads floating around on craigslist or in laying in scrap yards if yours are FUBAR'd up bad...it's also not unusual to find people selling brand new vortecs with big valves and springs for cheap that they'd gotten for a project that they lost motivation on

 

I pulled the heads and found that the exhaust valve in #4 barely hit the piston and left a scratch. I'm taking them to a shop Monday to check out and re build. The cylinders look good and can still see the cross hatching and no wear ridge, but there is black oil coating under the intake on the block and heads. They are the good heads and hope there are no cracks

 

That doesn't just randomly happen. Something broke to cause it.

 

How many RPM's have you turned it? How long were there symptoms before you decided to do a compression check? Can you see the seat? Does it look OK?

 

Since Gary gives no info except "99 Tahoe 5.7", we have to assume that it is completely stock, including the tune, and therefore cannot be revved high enough to damage anything unless something else is broke or worn out.

 

Heads getting re worked, they said bad ethanol gas caused the valve to stick, and springs were ok. I tore them down and cleaned everything and saved $100. I did find a barely used spider assembly with the 8 injectors, and otherwise the heads look good, no cracks. I'll do a comp check on #4 as soon as I put the head on.
I wonder should I replace the lifters or clean them?

 

Got the heads back with new springs, seals, and valve job. The new springs tested 10 pounds higher than the old ones. Now its time to go to work in 99 degree heat. Head shop said the 060 heads were the first in a long time that came in not cracked.I bought new head bolts too.