Which type IV engine?

[John A.]

I've found two needles in an Alaskan haystack. A '71 411 and a '73 412. Will do the usual engine checks (compression, etc.) but was wondering if one year is better to convert and install into my '56 Bug. Both cars are in good condition (considering Alaska's winters) and are both worth restoring to get on the road. Is the 411 more "unique"?

Also, both cars are running the 1.7L engine. Can these be bumped up to 1.8L, 1.9L or even a 2.0L? What sort of case mods are required to fit larger cylinders?

I'm excited about owning a type IV. It'll be a great addition to the local VW club.

Thanks for your advice.
John A.