Not possible without major fabrication.
Yes, a 2000 GMC Jimmy hood is compatible to a 2000 Chevy Blazer. This is only on the S10 Blazer though.
Under the hood, on the driver's side of the firewall.
in the big fuse panel under the hood where is it under the hood
It should be in the power distribution box under the hood.
Front center of radiator support.
under the hood on the passenger side mounted to the top of the coolant reservoir
You lift the hood and look at the pressure gauge.
Go on google Images
As you are looking under the hood, it is back by the firewall on the left side
Under the hood, passenger side, firewall, close to passenger fender.
In 91 the Tahoe was based on the S-10 so no they will not work. The fullsize SUV was labled a blazer but it was based on the previous platform so no they will not work with the later C/K platform.
Look in your owner's manual and under the hood on a placard and you will find the answer to this question.