69 dash help

I am installing a center mount fuel gauge into an original non-
center mount dash instrument carrier. (69 ss)
The stock center plate appears to be molded in place and I can see no obvious mounting points. It looks like the plate must be cut out. Did GM make 2 different carriers for Tach & non-Tach cars?
Can anyone offer any advise from experience on this?
Any ideas would be helpful. Thanks!!- JOLT

You have to cut it out from what I've seen. The gauge should have a bracket that bolts to the top of the dash where the bolt goes through the dashes frame...says my assembly manual. Looks kind of like an "S" shape bracket.