Hey Tyrap!! Yes.....that part replaces the stock one - we have seen a number of these stock plates fail - if I were building my engine, that would definately be something I'd get.....seems the more power going to the wheels on these rhinos, the more pressure it puts on that plate and it just can't handle some of that stress.....
I am thinking this would be a good idea and if it is the same part all is well...er
If we are talking about completely different things please tell me...
Thanks.
Tyrap, we are making our own plates, but they are taking longer than expected. We did use an Alba Diff Plate in our last engine build, because it was available and the engine was apart. Ours are going to be fabricated out of Stainless Steel to keep the cost down (I think even billet aluminum would be plenty) and probably retail for $150.00 - $200.00 (not $399.00 like Alba - ouch ). It depends on building costs.... I did forget to check on your CP piston, so I will do that on Monday for you.
That Diff plate is very cheap insurance if you ask me. The 2 engines that I have rebuilt for that problem had a cost of about $3300.00 just to fix one failure (engine cases, gears, bearings, seals, oil, coolant, labor.....)
You should go out to Speedworld tomorrow night and see our prototype 800cc engine in action. We took it out tonight and it was awesome. A little extreme for an average Rhino owner, but nice for racing......
). It depends on building costs.... 
I did forget to check on your CP piston, so I will do that on Monday for you. 