4.0 Rebuild

[Rusty XJ]

I got the 4.0 out of the 94 parts vehicle I had, finally.  Before I put it into the ZJ I was going to replace most of the seals, water pump, thermostat, and freeze out plugs. Just wondering if anyone recommends doing anything else while I'm at it? For example replacing the oil pump or having the head checked and valve seals replaced?  The motor is from a 94 that had about 90k on it when I bought it but it's been sitting in the Jeep since early 2007.

Also, I know that the 4.0 seems to run better on Champion copper plugs but what wires does everyone recommend? We use Autolite wires at work just because they have the factory style boots on them and snap on easier. I'm looking for best mpg and maybe some performance.

[Rusty XJ]

Anyone out there running the Performance Distributors Firepower ignition setup? I was looking into it but I don't know if it's worth the price of $175 vs the $70 for the Accel Super Tune-Up Kit on Quadratec that includes the plugs.


http://www.performancedistributors.com/jeep4.0.htm
or
http://www.quadratec.com/products/55126_903.htm
or
http://www.quadratec.com/products/55126_028_07.htm

Any advice or recommendations would be helpful.

[etaucher]

The last tune up I did on my Jeep, all I did was go to Auto Zone, and get there spark plugs and wires. Now I didn't buy the CHEAP ones, I bought good ones, and my Jeep ran good after that.

[MUDDY]

why not just do msd .