Cam replacement

[V.waffe 3]

I was wandering if it is necessary to split the case on a type 1 to switch cams, or if it was done in a similar manner to switching a cam on a old domestic like 350 Chevy or 302 Ford? The reason I am asking is due to my need to get a cam that will take some of the strain off my stock 1600. I use my car for work and frequently have to transport two other men to and from work. I live in a very hilly city and have to try and grab as much speed as I can before hitting the hills. I was wandering if anyone has any expierence with either aircooled.net's split duration cams ( as I do not have Kadrons back yet) or maybe an early bus cam, early busses did use a similar engine didn't they?. If anyone could help me I would thankful, Ryan