Always a good , common-sense approach! For the same reason, I'm in the process of fitting a Lindberg '66 Cutlass chassis under the recent '64 Cutlass from Round2, not because it's the best choice, but because I had a complete chassis in a box of parts I picked up cheap. As for the 3" wheelbase difference on yours, like I said: a sixteenth-inch adjustment at each end is nearly nothing, so go for it! It will look perfectly fine. I was just throwing out options in case you might have had some odd parts stashed like so many of us do. (They accidentally accumulate over the years) Really digging your build, and Buicks in general!