Oil pressure gauge

[Hisroth]

I've got the original oil pressure gauge line coming through the firewall and what looks like a place where I could link a new sending unit to it and continue to use the old line/gauge instead of installing all new.

Anyone know if I can find a sending unit I can install somewhere that will use the same line style from a 70 c10 so that I can couple in right on the engine side of the firewall where it looks like a coupler already exists so I don't have to put in an entirely new gauge and everything?

Also, where would I install the sending unit in a 1993 350 motor? It's got plenty of old plugs in the block that are capped now where TBI stuff once went I believe.