As this deals with a schedule change and not a cancellation (you are still on SK507...) I guess you are limited to article 9.1 in SAS Conditions of carriage. (Had it been a cancellation 9.2 gives a few more options to the traveller.)

If the delay is such a problem for you, you should actually have the right to cancel your booking with full refund if your argument is strong enough...
Article 9.1.2 states that "If, after you purchase your Ticket, we make a significant change to the scheduled flight time, which is not acceptable to you, and we are unable to book you on an alternate flight, which is acceptable to you, you will be entitled to a refund in accordance with Article 10.2 and the provisions of Article 15.4 will apply."

What I'm not sure about however is whether the 1:20 delay of your flight is enough to be considered a "significant delay"... But I guess this is a matter for negotiation...