47-54 bed question.

[firebird73]

I have a question about 47-54 chevy beds.
can anyone tell me what the measurement is from the center of the rear wheel to the edge of the bed (by the cab) is?

My Dad and I are going to be making a crew cab and putting it on a new (1999-2007) 3/4ton 4x4 frame so we are trying to figure out what wheel base would work best either a suburban/avalanche or a crew cab silverado.

thanks.