The short answer is no;) Keep in mind that the crankshaft position sensor is attached to the block. If it is moved, removed, replaced, or disturbed in any way, the crankshaft position sensor relearn is mandatory. It is done with a high $ scan tool capable of initiating it. As far as the PCM is concerned, swapping the block would qualify as replacing the sensor and the relearn is necessary.

ok got ya... so all i need is PCM and wiring harness... if i bought the motor without all that then what do i do

Go buy it somewhere, you need it.

if i bought a new PCM from like Advanced Auto id still need to program it tho right?? or would it teach itself

It would need to be programmed, AND the crankshaft position sensor relearn would need to be done.... at a GM dealer.

and thats gonna be a big F you to my wallet lol... i went to get a key made for my saturn w/out the chip... they charged $75... needless to say i walked out of there with no new key

I believe captain hook to be very knowledgeable when it comes to these Blazers. however I disagree with him on the swap, I truly believe it is able to be done with the factory computer in the 97. I however have never done it but will be doing it this summer. and I will let everyone know if it works.

The '98 engine should start and run with the '97 PCM, but, the crankshaft position sensor relearn must be performed. If not, the PCM will use the data from the last relearn, which is now incorrect with a different engine. The PCM uses the data for making every calculation and adjustment to injector timing, ignition timing, injector pulse width, EGR, idle speed, cylinder misfire detection and identification, etc etc, the relearn data must be correct for the engine to run properly.

Ok so I'm getting a 2000 model motor out of a wrecked blazer with everything included .... now I'm starting to get mine prepared to be pulled and have no clue what I'm doing lol... I want to learn but this is harder than I expected

Seems like 2000 has a secondary air pump and your 96 does not. You'll get a service engine light for it.