Engine coolant temp sensor could be faulty, the one close to the thermostat housing with two wires plugged into it.
Will a 1997 blazer what work on a 1999 blazer????? If your talking engine, transmission, or running gear than yes. It is all the same.
I read somewhere that there is a recall for this issue, talk to your dealer.
I would suspect fuel pump failure.
no,oil will but temp will not
a car bomb
DRL = daytime running lights
Check for vacuum leaks.
195 degrees F
around 195
might be a clogged fuel filter
Yes. The original 4.3 is the 5.7 with the front two cylinders removed - it will bolt right up to the transmission, and accept the wiring harness. You will have to swap the Blazer's computer with one from a truck that had the 5.7 though.
Could be in need of a tune up.