66 Barracuda/Valiant gauge question

Here's a question for all you 66 Valiant & Cuda owners out there who are smarted than me.
Why is it that the 66 parts catalog listing has different parts numbers listed for the gauges used in 66 Cudas and Valiants?
I picked up two NOS Valiant gauges (Temp-#2587028 & fuel -# 2587027) thinking I could use them in my Cuda only to find there are different part number listed for the Cuda. The look exactly the same as the Cuda gauges so what is the difference?
Well if I can't use them, anyone of you Valiant owners need some NOS gauges (still in the boxes)!