The swing axle I have also scares me. When we were pushing it around the driveway it was making a pretty loud clicking noise in neutral. Still trying to find the thread on the samba
Ant.
The clicking aka as Clucking noise your hearing is usually a chipped Folcum Plate <= spelling? at the trans side of the Swingaxle. They consist of two half round pieces of metal that permits the axel to swivel. The older plates were just polished smoothed metal, but the newer ones. sold by Weddle Industries now have groves in them to help hold and lubricate the Paddle side of the swingaxle.
BTW. I just gave several-aaaa axels to Matt Steetle and last I at was at his place he had several dozen trans on hand. Both swing and IRS.
Or he can do a quick build Freeway Flyer, gearing etc of your choice. He has most parts on hand. He's very reasonable on his prices. And is actually the guy who builds the VW boxes for Savage, Rusty Wagen, etc, etc. He also does Honda, and Vette Race Boxes including the new Vetts, and many other Race stuff so knows his chit.
I think I remember the only difference is the rear body mounts. Something has to be cut or altered. Lots of people have done it. Search on the Samba for your year model in the forums section. %$oldcit
To switch from Swingaxle to IRS. Your need a pair of IRS rear axle arms, IRS axles, and fabricate or buy some IRS adapter mounts. I believe that Pete at Airkewld world has them. Here's Pete's link.
http://www.airkewld.com Yes, it can be done but welding and lining up the mounts are key..
Or.... Just swap the Pan to the IRS Pan like you mentioned, as most of the parts needed will already be on the IRS Pan.
Plus your never need to worry about a bent wheelCock. #banghead