Hey Engine Guru's: I need your knowledge

[Dweano]

Ok heres the deal. I found a guy selling port and polished and rebuilt heads for the 4.0L OHV. The fact that they are in my area and a very good price makes me want to snap them up. But I have a few questions.
First off I have a 96 4.0L that I have done nothing to (well in terms of heads and stuff, whatever block and heads it came with from the factory are the ones it has now). Heres the exactly email he sent when I asked him about the casting numbers:
"One is off an early 90's explorer, and the other is a BRAND NEW CASTING, cause the mate was cracked and in the middle of January it was to cold to go find another used one so I had to bite the bullet and go for a new casting. I told you I am into them for LOTS. They have been on my shelf in the garage for 2 yrs and I have think that somebody else might as well use them."
So will that work for me?

Second. What should I ask him? Like I don't know too much but I know when he says brand new casting there has to be more than one possibility of what it could be right? Does it work to mix and match old heads and new? If there the same casting number it should work right?
Thanks for helping out the newbie guys!

 

[Bird]

If they're early castings (pre-95), you'll lose about 1 point of compression = 8:1 instead of your current 9:1.


Bird

 

[Big Jim M]

If your present heads are doing fine...why in the hell would you want to get these heads that in truth you know NOTHING about? If I had heads that I wanted to sell I'd most likely say ANYTHING to get rid of them..or anyway lots of guys would.
Ask yourself WHY he has heads on the shelf that he hasn't used in years.
BTW even with the best of grinding jobs them heads won't show you ANYTHING..
Big JIm

 

[Dweano]

Well my heads are getting up there in kilometers and the thought of fully rebuilt and P&P heads (and lower intake manifold) appeals to me. He's selling both heads and the lower intake manifold for $400, I could probably get them for $350...but I don't like the sound of losing compression...
Edit: Also it would give me a good excuse to change gaskets to better ones

 

[Big Jim M]

Also it would give me a good excuse to change gaskets to better ones !!!

Please tell me how it would be possible to get better gaskets than the ones that are presently WORKING FINE?
Perhaps I should pass along here some advice my old Dad gave me.. He said " if the son of a bitch ain't broke DON'T fix it".. Words I have tried to live by.
Big JIm

 

[shaysman]

i wouldnt buy them one anything could be wrong with the ones hes selling and two if the ones on it are working then leave them till they do mess up

 

[Dweano]

Also it would give me a good excuse to change gaskets to better ones !!!

Please tell me how it would be possible to get better gaskets than the ones that are presently WORKING FINE?
Perhaps I should pass along here some advice my old Dad gave me.. He said " if the son of a bitch ain't broke DON'T fix it".. Words I have tried to live by.
Big JIm

Haha doesn't felpro make a set that are supposed to be good? I dunno...just preventative work I guess. I do not want a head gasket blowing...ever. But from everything Im hearing I will stay away. Thanks guys

 

[Frank The Tank]

Do they make head-studs for the 4.0? i had them in my diesel ARP headstuds...... a lot of guys would replace them one at a time, when they started getting up in boost a bit. I o-ringed and headstudded at the same time and said be done with it (i had also blown 2 headgaskets and cracked a head allready)

but that's a thought.

Frank

 

[Dweano]

I told him I would pass on the heads because I would lose compression and heres what he said: These heads where shaved .015 (15thousands) to raise the compression. I think I could cc the chambers and you could do the math if you know what pistons you have. It just seems that these are the deal you have been waiting for and I would like to see them used. My 4litre seemed to work good with them.

I asked him if the two heads are the same style and everything with one being new and one being old and I asked him what year 4.0L he had them on.

 

[F150hybred]

Head shaving over .010 is risky at best. The material removed makes the heads more prone to warping and cracking. 4.0's didn't have all that much material to begin with. Walk away. That amount isn't gonna get you back that missing one point.

 

[Dweano]

Alright thanks for the info guys!