My buddy's '63 PU had the 327/Powerglide combo.
My '63 Impala had the same motor/tranny, too, but was de-stroked to 302 and ran 12.5:1 pistons. Shifting at 6000 RPM put it at between 50 and 55 MPH!
yeah....you think of a truck with a small block and imagine that it should be fairly quick but on the freeway here in CA you hit 60mph and it sounds like it's going to fly apart at any minute. I have a 350 transmission we are eventually going to put in it but we don't have the time to add it to this job right now. A third gear would be lovely though