2000 XJ with a 0630 Head. How to revert to 0331?

I know, I know, first post and it's a wall of text...

I apologize in advance.

After six weeks my new to me 2000 Cherokee Sport with 4.0 engine started showing signs of a cracked head, (i.e. loss of oil pressure when warm, mysterious loss of coolant.) So I did my research and learned about how so many of the 0331 cylinder heads from the 2000 and 2001 xj's self destruct.

So I bought a junkyard 0331 TUPY head and spent the money to get it cleaned, crack inspected, brass valve guides installed, etc. etc... Spent too much money.

So I had everything I need (or so I thought) to swap the heads, but when I get in there I see that my XJ has been previously retrofitted with a 0630 head as well as older intake manifold, exhaust manifold and power steering pump.:smsoap:

Even though the new head is no longer a simple swap I want to go ahead and put in the newer TUPY head and I want to know besides the newer two piece exhaust manifolds, the larger intake manifold and the new style PS pump is there any thing else I need to be aware of?

So far I've located the correct intake manifold for $50 but it's been ported to match the holes in the head better. A bit of research tells me that besides giving the engine a bit more top end power it will also make it run richer. Is this anything to be concerned about or will it be good to go?

Lastly, when the previous owner made the parts swap, he removed the catalytic converters. I'm wondering how much trouble it will be to make the new style duel exhaust manifolds join to the current exhaust pipe? Is this something I can have an exhaust shop take cake of or is there a Y pipe I can buy and make work myself?

Thanks in advance for any help offered.

Bump.

You can keep your current p/s pump that will bolt onto the newer intake manifold. You can also keep your current exhaust system, because the ports on the earlier style exhaust manifolds will cover the smaller exhaust ports on the 0331 head. Are you sure you don't have a cat before the muffler? If you do, don't worry about the ones that might've been attached to the manifolds(called precats, and only if your XJ is a Cali-emissions model did it come with them).

Well alright, that's good news.

Glad to hear I don't need to change any of the exhaust components right away. I wasn't aware that the precats we're specific to California jeeps. And no I don't have any cats on my jeep right now. This might change in the future though.

Thanks for the information.

The 00 was the last year of the cali/fed emissions, you most likely have a federal emissions jeep. The million dollar question would be is if you currently have a CEL.

But first, what's a CEL?

:dunce:

Okay CEL = Check engine light.

And yes I sure do.

I've got the 0630 head off right now and once I put the 0331 on this weekend I'll get the jeep scanned and find out what it's telling me.

To be continued ...

Any updates to this?

Inquiring minds want to know!

(Y2K XJ owner here, trying to learn everything he can about replacing cracked heads BEFORE the time comes when I HAVE to do it.)