0331 to 0630 Swap Kit

[wilsmick]

As a result of my 0331 head cracking and all that stuff that we all know about, I made an adapter plate for myself so that I could use an 0630 head with my stock '01 exhaust system.
My Jeep - 2001 XJ Limited 4.0
My Exhaust - 2 cast manifolds w/ 2 pre-cats and 4 Oxygen sensors.

For those in doubt, if you have the 0331 head and the exhaust described above, your exhaust manifolds will absolutely NOT cover the exhaust ports in the 0630 head. I can't comment on other exhaust systems, but is suspect that if you're changing from any 0331 head and you have a stock exhaust, you are probably going to have an issue.

If you're like me, you don't want to replace the 0331 with another 0331, but you also don't want to replace your stock exhaust just because of the exhaust port issue in the 0630 head. This is why I made myself this adapter plate - to solve this problem. It gets sandwiched between the head and intake/exhaust to effectively block to portion of the 0630 exhaust ports that aren't covered by the stock exhaust. The stack-up goes like this:
0630 Head
0630 Intake Exhaust Gasket
Exhaust/Intake Adapter Plate
0331 Intake/Exhaust Gasket
Stock Intake and Exhaust Manifold

Also, the 0630 head doesn't have the standoff's to support the ignition rail. I bent up some aluminum brackets that support the rail from the valve cover studs. I'll sell those too if people want them.

$150 - 0630 Exhaust/Intake Adapter Plate
$25 - Ignition Rail Brackets with all mounting hardware. I can have these black anodized for additional cost if you're concerned about calling attention to them, or if you just want them to look cool. I'll have to check, but I think I can get it done for cheap money.

Neccessary Additional Parts to do the swap (meaning that you need to get these yourself)
- 0630 Head (duh)
- 0630 Head Gasket (I used OEM gasket from '98 XJ) - approx. $50
- 0630 Intake/Exhaust Gasket (I used OEM gasket from '98 XJ) - approx. $15

Kinda optional parts
- 0331 Intake/Exhaust Gasket (mine was okay so I re-used it, I'v been told not to do this though. Mine seems to be fine)
- Cylinder Head Bolts (I didn't bother - FSM says that they are okay to re-use once)
- Valve Cover Gasket (I replaced, but stuck with the re-usable kind from the 0331 head)
- Thermostat + Thermostat Gasket - approx. $7

Here's some other tips if you're starting with a junk yard 0630
- Take it to a machine shop, check for flatness, valve seat condition and cracks
- Valve Lapping Compound (if you didn't have the shop do a valve job and you're there anyway, you might as well lap them, I did)
- Valve Stem Seals - 6 intake + 6 exhuast (I used OEM from '98 XJ)

If you want a complete swap kit (including all/any of the OEM stuff), tack on $10 plus the OEM cost of the items you want, and I'll round it all up and send it in one kit for you. So the price will be $185 + OEM items.

Lastly - The only other thing (that I can think of right now) that you need to watch for is the Temp Sensor Plug - the 0630 head has a threaded hole near the firewall end of the casting for a coolant sensor (or something). Luckily for me, the head I used had the sensor busted off, but the threaded portion was still in the head, plugging the hole. So, I don't know what the thread is, but you still need to watch for this on yours.

Luckily for you, I'v been through this all now (mine went at 93K) and made a print of the adapter when I was making my plate. I even have some inventory of the parts ready to ship now.
-Mike