While I was searching through my old magazines for some info on an old 70s VW trike kit I came across this article about a Corvair trike. Since a lot of our members are not "Older than Dirt" like me and all this happened BI (Before Internet), I thought I'd post a copy of the article for informational purposes.
The article mentions the builder's solution to the reverse rotation problem of a front mounted Corvair engine. VW bus reduction boxes are getting harder and harder (expensive) but they are still available and a viable solution. This does seem to limit the suspension design to pre-65 (swing arm) Corvair or pre-69 VW suspension.