Can you ?
 

is a 3 cyl. gas the same block as the diesel from a 1772 I like to put one in my 1872 but I know that the 2182 they are turn a 180deg.

Motors are the same yes. Yes, it has to be installed "backwards" just like the diesel. As long as you are talking about the Kubota gas motor, like the one in a 2182.

k thanks that what I thought I like a diesel but that another fuel to have on hand and there no other diesels on the hill but if it gas and I run out I can get some from my dads tank.

The engines sit the same in the 1572, 1772, 1782 and 2182 although the radiator is up in front of the engine location on the 1572, 1772 and behind the engine location on the 1782, 2182. The engines actually sit in them the same direction as other cub models do with the pto (shaft) end forward driving the attachments, all rotating the same direction. Hope this helps.