THEPATRIOT

I know the "00-"01 XJ heads are prone to cracking,and i believe the "99-had the same problem.What are the options to fix the problem?

SeriousOffroad

Get a 7120 or 0630 Casting

THEPATRIOT

What year head would i need?I have a "99 GC with a bad gasket,and think maybe the head is cracked.

SeriousOffroad

Year............Casting No
1987-90......2686
1991-95......7120
1996-99......0630
2000-01......0331


There area number of threads on NAXJA.ORG about fabbing cheap brackets to secure the coil packs.

THEPATRIOT

Thanks,is it a direct bolt up swap besides that?

SeriousOffroad

Yes

aj6

yes 0331's do crack

but there allways a good side

http://www.jeepstrokers.com/forum/vi...php?f=34&t=241

huntingman2706217

hhmm... buying buddies 00 WJ with a blown motor so they say... bet this was the cause...

THEPATRIOT

I'd like to get a rebuilt head ready to go(if i fix it).Where's a good place to get one?Also,where are the casting #'s?Thanks

SeriousOffroad

Any junk yard.

The number is on the drivers side, top, next to the valve cover.

5-90

2002-2007 WJ/WK/TJ will have the #0331 head with the revised casting. The problem seems to have been in 1999-2001 #0331 heads.

Any #0331 head will be a direct swap, including mounting the coil rail. If you go to a 7120 or 0630, you'll need to do something about the exhaust ports (they're smaller on the 0630, with the primaries in the header being correspondingly smaller. You'll get exhaust leaks if you don't do something about it, and 1999/2000-up headers with the precats are difficult to deal with on swaps...) and fabricate hanger brackets for the coil rail (which is really pretty simple to do. Most solutions have the coil rail brackets attached tot he head using the valve cover screws.)

The heads of 1975-up AMC inline sixes will otherwise swap around mechanically.