Question - who supplies a reman head (that is reliable)?
I was looking at this (correct #2686): Jeep 4.0 liter 6 cylinder head casting number 2686 - remanufactured
Opinions?

Not ready to sell of my jeep yet. It has rebuilt differential (all gears, no clutches) and transmission.
All of Cruiser54's upgrades completed.
Thanks for your guidance.
RV

 

Help to upgrade your profile to say what year Cherokee so we aren't guessing if you have the infamous cracked head problem

 

Bump.

 

My vote is always a valve job unless you have a cracked head. But they should find that if you get a good shop. I brought my 97 to a pretty reputable place, was ok. What I like is you can tell them for sure what you do want for sure, like I opted for all new exhaust valves and new springs. But they should find big improvement will come from new lifters, and most of all you absolutely must “ set the preload” of it will be sounding like sewing machine and munch itself and or crush the lifters. Many threads on this. This does not mean torquing the bridges, it means setting preload. They are not “ non adjustable “, setting preload is in fact the way you adjust them. If you just slap it all together and hope for the best you’re gonna be very unhappy and asking why do I have dry lifters but one is shooting up 2 feet of oil. In typical jeep fashion the manual says nothing on how to do he procedure.

 

The old guy who I trust retired so I can't help you there.

Have you thought about swapping on the head from a 91+ H.O., a 99+ horseshoe intake manifold and 12 hole injectors ?

The H.O. head gives a little bit more power at all RPM, the intake gives a little extra torque and the injectors give easier starts and better throttle response.

 

That's an interesting thought - would the truck still be able to pass whatever the requirements are for California smog? With that kind of mod, there would always be something else to do, like exhaust manifold, etc.

 

You would lose your EGR, so I'd imagine you would not pass visual inspection even if you passed the smog.

 

Here is what Google AI has to say:
To modify a 1988 Jeep Cherokee while complying with California smog laws, you must ensure all modifications have a CARB Executive Order (EO) and are installed on the specific vehicle listed in the EO. For emissions compliance, focus on performance upgrades that are smog-legal, like a high-flow exhaust system with the correct EO number, and ensure all original emissions equipment, including the EGR system and stock air intake, is properly functioning and in place.
What to do for smog compliance

• Verify EO numbers: All aftermarket parts must have a CARB Executive Order (EO) number to show they don't increase emissions.
• Install a compliant exhaust: Some headers and exhaust systems are smog-legal and may improve flow. Ensure it has a CARB EO number for your specific vehicle.
• Maintain or replace the air intake: Keep the stock air filter box and hose. If you must replace it, ensure the aftermarket part is also smog-legal and has an EO number.
• Check and repair emissions equipment:
  • EGR system: Ensure the EGR valve is not clogged, vacuum lines are connected correctly, and the switch is functioning properly to avoid high NOx levels.
  • Evaporative emissions system: Make sure the charcoal canister and purge valve are operational.
  • O2 sensors: Replace with new ones if they are old. The new ones must be installed in the factory locations and orientation.
• Ensure the engine control unit (ECU) is correct: The computer must be the correct one for the vehicle. Make sure the "Malfunction Indicator Lamp" (MIL) and "On-Board Diagnostics" (OBD) port are visible and functional.
• Have an initial referee inspection: After an engine swap, you must get an initial inspection at a state referee station to get a BAR Referee label.

Common pitfalls to avoid

• Illegal "tuning": Many aftermarket performance tuners are not legal in California for vehicles 1976 or newer, even if they don't affect emissions.
• Missing emissions equipment: Even for parts that are not visible, such as injectors, you must ensure everything is in working order. A non-stock air intake tube, for example, can cause a failed inspection.
• Incorrectly installed parts: Components must be installed exactly as per the instructions or OEM specifications.
• Engine swaps: Swapping the engine is an option, but it requires passing an inspection at a state referee station to ensure all equipment from the donor vehicle is correctly installed and functioning.