there is a ad on craiglist posting a 98 blazer with a 2003 motor in it..by the picture, could this be true?

 

To use the newer 2003 engine in a 1998 truck, the intake manifold would have had to have been swapped to retain the EGR system.


The knock sensor mouting would have also had to have been changed to utilize the single wire knock sensor.


The only real way to tell is to pull some numbers off the block.

 

that's what I thought...in picture it has the older style egr on the front of the engine

 

It has the EGR on the front because the older truck's PCM needs to see the EGR valve and have it functional or it would illuminate the check engine light. It is very possible that it is a 2003 long block with a 1998 intake manifold and the correct remachine for the knock sensor mounting (open up the M6? straight thread hole to a 1/4" NPT hole for the single wire knock sensor).