i have a 1996 S10 4X4 with the 4.3 and the oil pressure gage is acting up. When idling it runs about 40. While driving or reving the engine it jumps up to about 70. I'm assuming this is the sending unit. Is that most likely it? If so how hard is it to change? and where is it located?

Thanks.

 

The sending unit should be located somewhere on the block, where exactly I don't know, but an auto parts store should be able to tell you when you buy a new one. I would check your connections too.