Under bed gas tank sender issue

[mikebGMC70]

So I am installing a 59 impala gas tank into my 1970 gmc c20. My dilemma is the sender unit. A 59 impala uses 0-30 ohm. I have possibly 2 choices but would like to hear input or other ideas.

1 use a 65 impala or universal sending unit and figure how off it will be on the stock gauge

2 use a 59 impala sending unit and get a smaller gas gauge.

I would like to put a tachometer where the stock gas gauge is but I’m unsure of the circuit board on the gauge cluster and whether I can hack at it.

Thanks again, pictures are of the sending units