...and you don't "just bash" the firewall in. You must relocate the wiper motor, because on the 63 it's RIGHT WHERE the distributor needs to go. As much of a retard fabricator I am that'd make me stay slant 6 right there. LOL
I have heard both arguments, you can bash it just enough to clear and the wipers still work to you have to install a '64 firewall section and install the '64 wiper motor and bracket welded to upper firewall. I am not sure where the truth lies.