95Blazer old engine had crank sensor. The new one does not. What all is involved in swapping distributors.

 

Your truck must have been a late 1995 example which came with the newer EDI ignition control system and as close to OBD2 as '95s get. As such, going backwards would be quite the challenge as the PCM will be looking for certain things that are not present on the older design replacement engine. For your PCM to be happy, you'll need a CKP sensor. So a simple distributor swap isn't going to solve your issue and I do not know what is involved with attempting to swap the CKP related parts onto an older block/crank. I would think for it to be a mid-model-year change that it should be possible.

 

I already transferred the heads and CPI from old engine to the new engine. The old engine had a crank sensor the new engine doesn't. What all is involved to swap the distributor from the horizontal style to the vertical style!

 

If you wanted to step backwards (convert your EDI truck to the HEI distributor with vertical plug wire towers), you'd need to start with an older ECU and alter the harness to suit. This is no small task which is why I am recommending you look into what is required to put the CKP sensor, tone ring, and front cover onto the older engine you have. It is quite possible that it is a direct swap, but I have never read of anyone attempting this.

Makes me wonder... What did the replacement engine come out of?

 

The replacement engine is a 91 throttle body 4.3. I bought the 95 Blazer with a blown engine. The replacement engine came with it. So I swapped the heads and CPI injection onto the replacement engine. If they make a conversion kit for the crank sensor to be installed on the older engine that would be great. I do know where a older pre crank sensor Blazer is if I need to swap the pcm and harness.

 

Probably too old of a block to be able to have a CKP sensor & tone wheel installed, but might still be easier to check than to go through with ECU/harness conversion and all of the headaches likely to result from trying that out... Your call though. If it were me, I'd stop the basketcase scenario at the source and find the correct block for the application.