help-buying 97 blazer with a dead engine
 

I'm probably buying a 97 blazer from a coworker he say his engine just died out and I have a spot to buy a complete engine but its out of a 2002 is it the same type of engine?

puting a 02 motor in a 97 will not match up to the trans

What's the difference

Well, what jaked up posted isn't 100% accurate. The engine & trans will bolt up together just fine. It's the dust cover that might not work quite right if your trans has one. The '02 motor will have an aluminum oil pan, but that doesn't mean you can't swap the pan from your '97 motor if yours is steel. If you have an aluminum pan, it's a direct swap.

There are other differences though. The '02 engine will likely have a two wire knock sensor that bolts onto the back of the bell housing instead of threading on. The block will have to be drilled & tapped for the 1/4" NPT threads required for the older knock sensor. Also, the lower intake manifold may not have provisions for the EGR valve or the coolant temp sensor in which case, you will need to swap your lower intake manifold over onto the replacement engine. In that process, keep the injection spider as it will be the upgraded MFI spider.