Converting a loaf cake to a traybake!

I want to turn a loaf cake recipe into a tray bake. The cake is usually baked in a 900g loaf tin but I want to bake it in Delia's 26cm x 20cm oblong tin. Are there rules for success? The recipes says to bake it for 60 mins in a loaf tin. I presume that as the mixture is more widely spread out it will not take so long to cook? I don't want to end up with a dry cake.