I used the Calmini kit on mine without welding. Works great!
See this article at izook.com:
http://www.izook.com/tech/samurai/engine/1600swap/tech1600motor.htmDepending on how you want to set up the aspiration, it gets a bit complicated and expensive.
The ultimate way is to use a adapted engine harness, ECM and 1.6 Fuel Injection system. Benefits: reliable offroad operation at unusual angles, low maintenance, good fuel economy. Problems: rebuilt harnesses can be expensive.
Most of the big aftermarket suppliers offer rebuilt harnesses -- Trail Tough comes to mind...
Another way is to use a 1.3 head with an aggressive cam and a Weber carb (DGAV 3236 is a typical unit). Sarge at Midwest Performance
http://www.performancewebers.com/ has a nice setup that includes a slightly-modified intake that improves operation at unusual angles. This is what I run. My head and cam came from a well-known vendor but I cannot vouch for his ability to deliver on his product without severe brow-beating over the phone (no, it isn't Rocky Road...) Benefits: simple technology (read NO rats-nest of vaccuum hoses!), no ECM, okay fuel economy, costs a little less.
If I had the 1.6 WITH the harness and the ECM, I'd get the harness rebuilt as the cost would be a toss-up but the reliable odd-angle operation would be a big plus!