I was wondering if there's an potentiation number to find out what year the engine itself is. I have a 96 and supposedly the engine is from a 99. Is there anyway to tell if it truly is from a 99?

 

I should know this..but I forget. On the left side of the block, forward, below the manifolds? Or there might be a # on the right.

Then check it here > http://www.jeep4.0performance.4mg.com/tech_specs.html

Looks like 96 to 99 used the same block. >> 1996-99......53020569.............................48830 25

 

Passenger side near the distributor. Up and a bit to the right. Engine date code.



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. [*]

 

Well it isNT the stock engine but also is not from a 99. The code is 706MX06. So that would mean its from a 97

 

OK.

 

Appreciate the help