Take a look at these heads and tell me what you think...

could be either. i would check to make sure the valve giudes have'nt been knurled though.....Allen

If they have been 'knurled', what does that mean and why would it be a bad thing?

At first look I would say more than 10k miles not 1K.
You wouldn't see that much carbon build up with that low a milage,but if he had a worn lower end(bad rings) that would explain it

What are you doing looking at heads??!!! I thought... Oh never mind!!!

You know what a knurled knob looks like right? They do the same to the inside of the guides,
when you press the cutter in , it raises metal around the teeth so the stem fits tighter.Kind
of a poor discription but you get the idea. It's a quick fix bandaid instead of replacing the guides,
and imo don't last too swell.

Knurling guides is generally done on low-end rebuilds for stockers...definitely not something to consider for performance use...

You (or the seller) can pop a valve out (an exhaust would be a good choice) and check the guide. Tell us what you find (I loathe leading questions..*G*)...

IMO, uneven combustion for such a new set of heads...I'll assume the engine they were on was older...

If the price is substantial, get a written warranty of fitness (eg no cracks, surface warpage, parts condition, etc)...if no warranty is forthcoming, I wouldn't pay more than 100.00 for the set...and would inspect them carefully.

Good luck!

Look at a pair of GT40 heads on 97 Explorers I think they used them up till mid 98 too before switching to the GT40P heads. The GT40's will have hardened seats, flow better and you can put roller rockers on easily too.

I've looked at these a lot. Don't they have weird spark plug problems like getting in the way of headers? I want to be open to the choice of headers I use so don't want this limitation...

The GT-40P's are the ones with a different spark plug location. The GT-40's will work fine with your stock headers. I am not sure who it is but someone makes headers for the GT-40P heads in an early model mustang, I think. The GT-40P heads take a different spark plug as well.

The seller assure's me they were rebuilt 1000 miles ago

*LOL*. I've heard that one before /forums/images/icons/wink.gif. If he can't produce a receipt, buy them for the price of a core. Those don't look like rebuilt heads by any stretch of the imagination.

He sent me a picture of the paperwork but it had no date...