Speeds to fly for Two-Up cross country in ASK21?

Am going to fly a club K21 in the upcoming contest at CCSC and have
been trying to find some basic speed to fly data.

What I have so far is Schleicher says( in an on-line brochure) that
the L/D flown two up is 34 at 90 KMH...so I interpret that to be about
49 Kts.

They also say that the stall speed flown two up is 35 Kts

I find no mention anyplace of Minimum Sink Speed. From the polar in
the brochure it looks to be about 42 to 44Kts.

I have a some cross country time in the K21 and these speeds look
reasonable to me but I'm not sure.

Anyone have any suggestions regarding speeds to fly the ASK21 ?

From the above data on a weak day I might fly 55 kts or so. On a good
day with cu's maybe 60 or even 65 kts. Any rules of thumb you would
like to share ?

Thanks,

Jim