Non-HO (Renix) Block Casting Change?

[ratherbcamping]

I've searched the forum and my manuals and can't find the answer to this one. The 4.0 in my 89 XJ has 5 - 2" freeze plugs on the manifold side of the block. The replacement engine I bought, which was already out of the XJ, has 3 - 2" freeze plugs and 2 - 1" freeze plugs between them. This engine still had all the Renix gear on it and I was told it came out of an 88 XJ.

So, did the block casting change between 88 and 89, or am I looking at a 4.2l engine? Everything seems to be the same other than the freeze plugs.

[Dr. Dyno]

What's the casting no. stamped on the driver's side of the block? If you can give me that, I'll identify the block for you.

[ratherbcamping]

Hey Doc,

Drivers side: first is 08 6 87 (which I'm guessing is the date cast) and then EF8933002665BT

Passenger side: (stamped, not cast) 704M16

Thanks,
Tom

[Dr. Dyno]

The engine no. 704M16 means that it's an M block (4.0) that was cast on 16th April 1987. The casting no. EF8933002665BT is that of a renix 4.0 block.

[ratherbcamping]

Thanks Doc!

Tom