I have a 1980 El Camino with buckets seats and factory console and floor shifter with turbo 350 3 speed auto. My plans are to remove the T350 and install a 200r4 from a GN. I ASSUME I will have to replace the factory 3 speed shifter and get a factory 4 speed shifter (dont want an aftermarket shifter). When looking at used factory 4 speed shifters is there a way to tell the difference between the two? When I see ads for them they always look the same. Do they use the same mounting holes on the transmission hump? Thank you in advance.