87 V20 Suburban TBI 350 oil pressure sender for the gauge help

[93FatBottom]

I bought a new oil pressure sender at Autozone and went to install it, but the one that came off of it was 1/8" threads and the one the parts stores show is 1/4" threads. The 90 degree elbow has the 1/4" hole but there was a 1/4" to 1/8" reducer. The parts stores say the 1/8" sender is for the dash light but I have a gauge, so they keep saying it won't work. Has anyone encountered this issue before, and if so what was the outcome? About to start driving this thing daily and need my gauge lol.

Autozone ordered me the 1/8" sender since it's cheap, so I'm gonna buy it anyways and try it, but thought I'd ask here if anyone could tell me if I would be wasting my time or not?

Thanks in advance!