I keep finding mixed things about the meaning of this block code. Just about the only thing I have been able to figure is that it was manufactured in September of 1962.

409MXI2

I need to install a timing chain kit and am not sure which to get.
Any help would be greatly appreciated!

 

4.0 Engine date codes

The date code is on the passenger side of the engine, on the block, just forward and up from the distributor on a machined flat surface.

The digits of the code identify:
 1st Digit-The year (8 = 1998).
 2nd & 3rd Digits-The month (01 - 12).
 4th & 5th Digits-The engine type/fuel system/compression ratio (MX = A 4.0 Liter (242 CID) 8.7:1 compression ratio engine with a multi-point fuel injection system).
 6th & 7th Digits-The day of engine build (01 - 31).
1. FOR EXAMPLE: Code * 801MX12 * identifies a 4.0 Liter (242 CID) engine with a multi-point fuel injection system, 8.7:1 compression ratio and built on January 12, 1998.

 

1962?

 

you need a chain kit for a 4.0! build date won't affect that.

not 1962. 9/12/94

 

That's what I was thinking, isn't a 4.0 a 4.0? Looking at the part# change over the years (a 1990-94ish compared to a 97+), looks like the chain itself and crank sprocket are identical, the cam sprocket changed some though. Are you trying to get an OEM set?

Remember to replace the tensioner/damper that sits in the timing cover too.