How many differnet final drive ratios were available for 930?

[blue72s]

According to PET, there are only two ring and pinion ratios available for 930 (4 speed):

9:36 and 9:38

But in the following thread RUF 930 5-spd, History? Info?, somebody has said you can get like 8:39 or 8:41. Was that chap talking about aftermarket rings and pinions or what?

So, how many different OEM r&p ratios were available?

Thanks.