the larger of the 2 lines that come off the compressor
Larger hose from the compressor
I don't know about the 91, but the 04 has the high/low switch in the liquid line[the small line] over on the passenger side adjacent to the condenser[in front of the radiator] Look for a sensor with electrical leads.
Check bulbs Could be bad switch (hi-lo)
no
... what about them?
Yes
No, gear ratios are different.
autozone website i got mine off of there for a 91 camaro
Around 1-3 MPG less in both city/hwy
Check
whats wrong with it?
305 or a v6