i am swapping a 350 out of a 92 blazer into my v6 83 firebird. can i keep the v6 oil pressure gauge. it reads to 80 and i bought a 80psi gauge for a 83 sbc. also i used an adaptor and put it in right about the oil filter and plugged the hole by the distbutor. will this work. thanks

 

No problem I can see w/ using the threaded hole above the oil filter boss instead of the threaded hole on top of the block's rear china wall. You'll get a good indication of overall system pressure at either location.

As for using your old dash gauge, no clue. You can find out by comparing the resistance values of the sender you bought (available from the manufacturer) against the resistance values of the in-dash gauge (available in a Helms manual most likely).