455 Olds Rocket into '79 Trans Am - Oil Guage doesn't work - Help!

Hello All,

I finally hooked up my '73 Olds 455 Rocket into my 79 Trans Am. It's sounding mean & moving fast, but I cannot get the oil gauge to work in the dash.
I know I have the correct wire. (Dk. blue) because when I ground it, the gauge goes to 0 PSI of oil. When I disconnect it, it goes all the way to the right. I am concerned that the '73 Olds oil pressure sending using will not work with the '79 Pontiac gauge. I bought a new (455) Olds sending unit because I wasn't getting a reading, but I still can't get any indication of any oil pressure. I cannot use the '79 (403) oil pressure sending unit because it doesn't fit. It is too huge! Does anyone have any ideas?

Thanks guys!

get some fittings and do some adapting

What is too huge? The sending unit itself or the threaded portion of the sending unit compared to the hole in the block? If it's the sending unit itself you can remote mount it using a metal line or you could use a flexline but you would have to figure out a way to hard mount the sending unit to the firewall or on the engine somewhere like on a manifold bolt or something.

The size of the adapter does not fit. The adapter for the '79 is barrel-shaped and is like two inches across, I only have one inch of space behind the water pump. The oil hole for the threading is the same size.
It sounds like I will have to figure out some kind of a tube extension because I guess the gauge is looking for the sending unit that is normally on the stock 403s. I guess all gauges are not created equally.

Thanks for your help guys.

get some fittings and do some adapting

ding ding ding