Trans Tunnel Modifications?

they're reasonably close. I've got a '74 Dart hump in my '63 and it lined up pretty well. there is about a half inch gap at the back where the later trans tunnel is a bigger diameter but this could easily be hammered closed and welded up - and one day i might even get round to doing that on mine...

as far as gas pedal clearance, it's quite tight but a stock pedal could still be used. I've got a Chevy Astro pedal on mine because the '63 has a different firewall to the later cars and the V8 pedal setup doesn't fit