Working on a 1990 samurai with a 1.3L. The old head had locked up from lack of putting the head gasket on correctly.
So I ordered a new head from eBay looks slightly different but entirely the same as the casting I removed. The problem lies in the distributor housing on the rear of the head. The rear of the camshafts look different from each other causing a 4mm gap to form when bolting it to the head. (Pictures to follow when I can figure out how to post them) question I have is do I machine that one down? Order a new housing? Return and order a new head? Or make an adapter? Do I need a new distributor to go with it. Finding any wrecking yards with these engines is especially rare here in west Texas. Also any place recommend to find a new cam gear? Mine got destroyed when it locked up. Thank you.

I recommend Trail Tough for the cam shaft. They can probably answer the question and/or get you the proper part you need for the distributor too.

www.trailtough.com

If the new head does not have a mount for the fuel pump, I think you might actually have a early Tracker/Sidekick (89-91) head instead of the stock 1990-95 FI Samurai head.   The early Tracker/Sidekick was fuel injected and had a very similar head to the Samurai fuel injected head, but the early Tracker/Sidekick used a vacuum advance distributor that was different than the Samurai FI distributor and the later Tracker/Sidekick distributors.  It sounds like you might be mixing and matching parts that are not compatible.

Post some pictures.

Figured out the problems with the head, didn't realize that the camshaft is removed from the rear of the head, loosened the rocker arms and tapped the cam back into place and distributor housing fit well. Purchased a new cam gear and built a bracket for the egr vacuum valve to mount. Got it started and ran for 2 minutes before the fuel pump seized up. Fixed it and it ran for 5 minutes before it stalled and won't start with no spark. Cranking fine, distributor is turning and fuel injector is firing( which I assume means that the computer and distributor are working properly. Changed out the ignition module and coil and still no spark. Ideas?