I have a 1993 ford f150 4.9 I put a new fuel pump in the rear tank now the truck runs rough and gas gauge goes beyond full I think the mechanic did not get the wiring right
and can I lower the tank enough to look at wiring ANY suggestions thanks

 

If you paid him to do a job and it isn't right , you should give him a chance to do it right.
Your assumption could be correct, but once you touch anything , he is no longer responsible and you don't really want to be there .
You might ask if he knows what went wrong.

Dropping a fuel tank is not too bad a job if you are equipped to handle it. It can be very heavy if the tank is full of fuel.