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200-2001 Head questions

T

Team Willys

www.rocksolidfab.com
Location
Chattanooga, TN
Hey guys, I need to know if an HO head from like a 95 has the holes in it that the coil packs bolt to on the 200 and newer 4.0 heads. I am building chris's stroker and want to replace to crack prone head with one from an HO beacsuer it flows better and they are a better casting.

I'd just hate to built this thing and then the head let go after 1000 miles. But I may have to use it if the previous years don't have the mounting locations for the coils.
 
The older heads don't have the coil bosses. You will need a mid-1999 to 2001 head stamped #0331 unfortunately, or buy a Hesco performance aluminum cylinder head (which is aftermarket and has coil bosses, but will fit almost any year 4.0) or similar.
 
thethinginthewoods said:
The older heads don't have the coil bosses. You will need a mid-1999 to 2001 head stamped #0331 unfortunately, or buy a Hesco performance aluminum cylinder head (which is aftermarket and has coil bosses, but will fit almost any year 4.0) or similar.
Click to expand...


Well, while the hesco would be cool, im afraid its out of the budget...

Ill look and see what I find, but I doubt I'll have any luck on it...
 
trail rate this said:
Just build a small bracket.
Click to expand...

A small bracket?

Define small...

The bosses run from the rear of the head to the front, I believe there are 5???

I could probably fashion some sort of bracket, but it wouldn't fit at the same angle as the factory places since there ar other parts of the head in the way, also, there isn't a good place to mount a bracket.

Not trying to shut you down, but I already thought about a bracket, it just isn't that easy.
 
jb weld? grind off the stuff in the way? i wouldn't wanna build a motor with a chance of the head crackin. if the head cracks, it would look bad on your track record of motor builds, and it wouldn't even be your fault. jeep should have recalled all the 0331 heads....
 
No, the 0331s are the good ones...

And JB weld! ARE YOU KIDDING ME?

LOL.

Dude, I can't build an engine and JB weld parts on it...

That's very unproffessional. That would be very bad on my track record for engines. Trust me, it'll be done right whatever it is, that's just how I am, I don't halfwway do anything. You will see when you get that awesome 360 you've been talking about, its gonna be sweet.
 
Last edited by a moderator:
ha, my bad.... we have a wall of jb weld built up in the middle of our piston heads on a nissan motor we built to run on hydrogen for mtsu. we needed a way to keep the hydrogen and oxygen from mixing until ignition. we didn't want to turn it into a water making machine.:D
 
Chief

JB weld isn't going on my motor. Even if Tyler was ok with it I'm not. I've used it for motorcycle engines while stunting and it's ok. But this isn't a throw away 600cc motor. No offense and I'm not being an ass but it's just not cool!

Tyler. I'm just shooting from the hip but I think that the coil pack is held on with just a few bolts into the head right? Is there a way to retrofit the coilpack onto the older head? I've only taken the 'pack of once so my memory isn't terribly sharp...and I didn't document with photos.


And OUCH. 2 grand for the Hesco head! I am tempted but I don't think I want to pay that much.

Did a little research and it looks like the 7120 head with the coil pack isn't impossible. Just a little engineering involved. Tyler you have PM's

If anyone's interested in I can put the links up here too for later reference.
 
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what about an alabama head? i was reading about the 5.0 stroker for the 4.0 that 505 performance had and in the article (jp mag) they used an alabama cyclinder head.

does the alabama head have what you would need? i think they are cheaper than the hescos...not sure though...
 
https://www.alabamacylinderhead.com/productdetail.php?id=109

that's a new alabama 4.0 head. They a long casting number which contains both the 7120 (what we want) and 0331 (currently installed) in the part number. So it may be a matter of either fitting the coil pack to the 95 head, or getting one with the fits for the coil pack such as this. The one year warrantee is nice on the alabama part though.
 
True to the point. It's a decent price. Tyler will probably chime in (when he finds this thread in the OE area and not the modified or street performance area because it's dealing with a stroker build). Sticklers for thread location on NAXJA huh?

I'd think the availability would be a key for this purchase. I've left most of the building decisions in his hands, well some!
 
What about later TJ 4.0 heads?
 
if the jeep stroker site is correct. From 99 until the demise of the 4.0 they all had 0331 heads on them. The consensus is that the 7120 head is the best for the stroker.
 
Team Willys said:
No, the 0331s are the good ones...
Click to expand...

No, they're not. They are prone to cracking between the exhaust ports of the 3rd and 4th cylinder causing coolant to mix with your oil.

But, if you insist on using the 0331 head and you have a budget of $400, look into some of the head rebuilders on e-bay selling (at least claiming to) 0331 heads with the "trouble" areas fixed.

I've got a 0630 head on my coilpack engine with no brackets. Coilpacks just kinda sit there...nowhere for them to go, but I do want to build some brackets off of the valve cover bolts/studs eventually.
 
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Team Willys said:
Hey guys, I need to know if an HO head from like a 95 has the holes in it that the coil packs bolt to on the 200 and newer 4.0 heads. I am building chris's stroker and want to replace to crack prone head with one from an HO beacsuer it flows better and they are a better casting.
I'd just hate to built this thing and then the head let go after 1000 miles. But I may have to use it if the previous years don't have the mounting locations for the coils.
Click to expand...

20 seconds of searching found this.
http://www.naxja.org/forum/showthread.php?t=937214&highlight=coil+rail
 
the 0331 head flows more air at the intake ports, and would be a better choice. also, it already is set up for the coil on plug. get one from a later year tj...like a 2003ish...they have been improved from the factory, and i havent heard of any of the later years cracking. the 7120 and 0630 heads are basically the same.
 
Building the coil brackets is easy. Don't let that stop you from dumping the 0331 head. I picked up a 0630 for $50 on craigslist. The "hardest" part is adapting the exhaust header outlet to the exhaust pipe. And a exhaust shop can take care of that easily (or DIY). Don't sweat the coil bracket. The coil basically rests on the spark plugs and the brackets you can easily make just stabilize the top.
 
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