I forgot to mention another benefit of the 6 rib will be much higher wheel speed when hillclimbing and a better ground speed for cruising the trails with less rpm.
A 2074 may not pull the gearing as hard as you want it to unless your buggy is pretty light. 5 rib gearing may suit you better, but they are no stronger than a 3. With the 6 rib n s/d you will have room to grow. Unless the 92 piston n cylinders are free and in perfect shape, it would not cost any more to go on up to 94's. Contrary to old school thinking, engine size is not real relevant to reliability. A good quality build by an experienced builder using top quality parts and a machinist familiar with AC VW's are the deciding factors in reliability. High quality oil, keeping your air filter(s) clean, external oil filtering, and extra oil cooling will also contribute. A dry sump will assure you are oiling your engine correctly when your buggy is pointed at the sky and you are flat footed and add lifespan to it also. Most people where I ride run engines quite a bit larger than 2074 and some have lasted 15 years of hard climbing nearly every weekend with just reringing a time or two.
Easy way to tell if you running a1915 is look under the engine where the studs go thru the cylinders . A 1641 will have a smaller bore in the block (or ' case' it is called in aircooled terms), so there will be 'meat' between the stud and the hole where the cylinder goes in. A 1915 requires the case to be cut bigger, so it will look like the hole is cut all the way to inner edge of the studs. Get someone who is familiar with them to look and they should at least be able to tell if its bigger than a 1641.
Judging engine size by what someone says will or wont go up a certain hill is goofy. Buggyweight, gearing, tire size and bite , and driver skill are more important factors than engine. Maybe you are just a better driver than that guy!
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