The fenders will bolt on without modification.  Your 70 has more bulbs in the tail lights than a 64 . . . you'll loose your back-up lights, but you can always add the 67 style bumper bracket mounted back-up lights.  That's not really that big of a deal.

The biggest "problem" is the bumper brackets.  I think the 64 brackets ran through the front apron instead of the fenders, and the brackets are larger on the 70.  You can modify one or the other and make it work, create some custom brackets from scratch, or if you can still get them, Rock Mountian Motorworks used to have some bolt on late bug to early bumper brackets in their catalog.



Edited By Zen on 1082761393

You can from time to time catch new fenders on sale at swap meets for as low as $50-60.  But if these are in good condition and are original German parts, your better off with the used ones over new ones even if they cost a little more.  Here's a quote from a guy from the shop talk forums who bought some mail-order fenders:

I answered my own question.... i went with the I.S.O's and if you dont mind a little (well a lot) of bending the flange where the holes are then these are great. But there thin, pre-scratched, rough, bent sides, and well....cheap. But they work with a little massaging.