So, I pulled the 4.0L out of the 99' Cherokee Sport (no compression in #1, 250K miles, numerous oil leaks). I bought a used 4.0L from a Wrangler with 70K miles and overhauled it (oil pump, water pump, rear main seal, thermostat, new-design of exhaust manifold, valve cover gasket, oil pan gasket, etc) and swapped over all the necessary brackets and pulleys to build the Cherokee configuration.

Now, I'm ready to put the 'old' flexplate/flywheel from the 'old' engine onto the 'new' engine.

My question is this: Can I pull the flexplate/flywheel off the 'old' engine and slap it on the 'new' engine without worrying about confusing the CPS (CPS slots in the flexplate)? Or, should I get both engines at TDC and note the position before I pull it off to be sure it's in the same position on the 'new' engine?

I think I'll go with TDC idea but I'm interested in hearing your thoughts.

 

Just install the 99 flexplate. The bolt pattern ensures that the windows for the CPS will be in the correct position.

 

Great, thanks. However, the bolt pattern looks pretty damn even.

 

It's not.

The flex plate has a bolt pattern that will only allow it to be installed in 1 position.

 

FrankZ is right. I learned this the hard way. Don't force the bolts in. It will line up one way.

 

Thanks guys.

I'm going to get new bolts Fri afternoon and hopefully start installing the 'new' engine shortly after I remove the old flex plate (I keep wanting to say Flywheel!) and install it on the 'new' engine.

 

I completed the engine swap last night. The Cherokee runs like a top now; she is really peppy, it's awesome.

You guys were right, the bolt holes are offset just enough to ensure the flex plate goes on correctly. The offset wasn't visually apparent until I started turning the flex plate against the 'new' engine.