Gents,

has anyone fitted this head? Happy? How many miles since installation?

I've had a 2001 XJ from new in England (It was called a Cherokee 60th Anniversary Edition here), and loved the thing, until.....It started mysteriously using coolant with no visible leaks, but, was picking up Mayo under the oil filler cap and turning fresh coolant dirty. It had done 63000miles and reading this forum the horror movie of millennium Cherokees with a craCKed #331 head between No 3 & 4 pots became all to real!

Unbelievably, looking in through the oil filler port with the engine running you could see beads of water ‘sweating’ out of the head along a 1cm (sorry we’re all European now) hairline crack that was invisible before.

Further research has revealed a problem. The #331 head can be bought remanufactured BUT could crack the next day after fitting. A 2002 to 06 Wrangler head stamped 331 TUPY, appears to cure the problem , but the biggest rebuild shop ATK VEGE can’t guarantee which type of head will be shipped if I order one. I know coz I asked!

Hence the question about Promaxx; Bigger, stronger, fits everything and a new casting.


Cheers

 

I feel your pain. I experienced the dreaded 0331 cylinder head crack just last week. I ordered a replacement head from Clearwater. I'm pretty sure it's the same head offered by Promaxx, which used to be Alabama Cylinder Heads.

I received the new head just this past Monday. I'm in the process of installing it. So, I can't give you any long term performance data. I can tell you in all appearances it's a quality casting and is definitely "beefier" in the area between cylinders 3 & 4. As a plus, the ports appear much smoother than the factory casting as well.

Recently, someone here posted he found a source for a remanufactured TUPY head. That would also be a good option and likely less expensive than the new casting from Clearwater or Promaxx. I don't know what source that was. All the reman sources I checked offered just another, standard 0331 head or they simply couldn't tell me what I would get. So, I went with the new casting with new valves.

 

Out of curiosity, did the engine ever overheat? You might have the record with only 63000 miles. Mine lasted around 173000 miles and replaced with the Clearwater head. So far so good at 185000 miles.

 

did you ever get around to instaling the new head? im curious about how it went, im also looking at buying a promaxx head