This is a very easy swap. Just finished up a 97 zj engine swap in my 2000 xj. Yes the exhaust ports are bigger. People say to use a conversion plate, but it is not necessary. When you are ready to bolt on the manifolds just use the gasket from the 0331 head. The exhaust ports are smaller on the gasket and compensate for the bigger exhaust ports on the 0630 head. Your not building a race car so the small amount of restriction you may see is no problem. Switching from distributor to coil on plug is also very easy. Set the #1 cylinder to TDC and make sure the engine is at 0 degrees before TDC. When you put the cam sensor in place of the distributor it should face the firewall. The 0630 doesn't have bores to bolt the coil pack down on the head. What I did as many other people have , was made custom brackets out of chevy starter shims. They can bolt up to the valve cover studs. Make sure to use the flywheel from your 2000 xj. All accessory drives and pumps from the 2000 will be used on the older engine. I resealed my whole engine before dropping it to make sure no leaks would be made. Use your 2000 intake as well. It's not much but it is a noticeable horsepower increase. I finished my swap off with a dynomax cat back. Very please with it

 

Well here ya go.

Someone who has actually done it.

How far off are the ports? 5/16" or less?

 

If that, noticeable because the new head is a square port and the older heads are circle. Obvious difference but not much

 

Interesting.

 

Point made and recognized.

 

Talk about interesting, hate to see that thing on a flow bench, or engine dyno to see the heat on those ports.

 

If your 2000 has federal emissions, 1 cat and 2 o2 sensors than it's easy. Install the 2000 intake on the 92 block with the 92 header. Swap over the rest of the sensors, use the tooth pick method to install the cam sensor and install the late model flywheel. Get the 2000 down pipe modified to the '92 header flange. Make brackets to mount the coil rail or install a viper coil pack with plug wires using SilverXJ instructions on Naxja.

That's basicly what I'm running on a 4.7 stroker but using a CARB legal header by JBA.