If i had a 63 square and a 73 square, could i put the 63 shell on the 73 floor pan? any info or ideas would be appreciated.thanks

Yes but would have to keep swing axle set up or have supports put in to hold rear engine bar.My car has a later floorpan

How big is the job Rocket?

Nothing with VW's is easy.Basicly you have to lift body up from pan.First uncoupling electrics and steering.In your case would have to change rear frame unless you make up brackets for engine support and keep IRS.Not too hard but a fair bit of work .Good Luck.