1st gen heads on 2nd gen block?

[EvilTheCat]

I pulled the heads off my '97 4.0L OHV and found that they are both cracked.
Now I need replacements.
I have found some off a first generation explorer on eBay, but I am unsure if they will fit the same.
Has anyone done this?
I couldn't find any info on this site (perhaps I'm not searching for it correctly)
I cross referenced the part numbers on rockauto.com.
They have the same numbers H3043, but for the 93, 94 and my 97 the numbers have an A or B at the end.
It seems that they may have different exhaust ports, but I still don't know what to do yet.
Any thoughts are appreciated.

 

[EvilTheCat]

I found some info after searching some more.
This thread has some info about the head style of the various generations, but it's still not quite what I'm looking for.
Perhaps I'll just keep looking for my style of head.

 

[racer_x_one]

I'm assuming you have an ohv engine, if so then they will fit/work, but you will have lower compression if you do. The 2nd gen heads are a smaller cc head and the pistons are a deeper dish to maintain the same compression compared to the 1st gen that had larger cc heads and smaller dish pistons. If you put 1st gen heads on your block you will have lower compression.

By putting used 1st gen heads on or any used for that matter your just asking for more cracks down the road. If you can afford it buy new from ebay, alabama cylinder or engine quest. Your looking for 95tm/97tm or 98tm heads. Both will work with your pistons.

http://www.ebay.com/itm/170400207578?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

[EvilTheCat]

On the link I have above "this thread" they say not to use later model heads since they have smaller exhaust ports and thus have faster moving exhaust which will burn up your cat.
Can I just pull the cat out or should it be replaced with later model cat also (no emissions testing here)?
It seems like everyone on eBay is selling older or newer heads (or they just plain don't know what they have).
Thanks for the link, but i am hoping to purchase completely new (as suggested) assembled heads, so I can just bolt them right on.

So lower compression from the older heads will mean less power right?
What I've read indicates that the 98+ heads will give a higher compression, so more power (once properly exhausted) right?

 

[racer_x_one]

No increase in power. 98tm's have the same cc's as what your stock heads are (95tm/97tm). 98 is when they narrowed the exhaust port from 1.70" to 1.40". Ford says this was done so that the increase in exhaust gas velocity would heat up the cats faster for emissions at start up.

I wouldn't totaly eliminate your cats. I don't know about how it would effect your cats, weather there basicaly the same as cats on 98tms or not.

I do believe alabama cylinder head and engine quest sells assembled heads.

http://www.ebay.com/itm/1995-2002-F...Parts_Accessories&vxp=mtr&hash=item2c60b985f2

 

[EvilTheCat]

It looks like there are many others who've looked into this.
Search 95tm vs 98tm to find lots of threads like this one.
I thank everyone for their input and interest.
I always encourage any opinion or idea, because it might just be the thing I'm looking for.

Engine Quest has the best info I've found so far about the different types of heads.

Here's the link for prices and such.

I still haven't decided which heads to go with. I'll probably just roll with these from J and C enterprises.
I sent them an email to find out what size exhaust port they have, but no response today.
I may just buy them with smaller ports anyway and see what happens.
What's the cost of discovery anyway?
One new cat, sure I'll try it, then others can perhaps learn from this trial and error (hopefully not the latter).