Can anyone here tell me how to build a 307 Stroker motor for my wagon?

 

It can be done, but it won't be cheap. You're MUCH better off getting a 350 or 403 olds and just doing a rebuild on that if you want more power.

 

I don't think you can buy a bigger crank for a 307 but you can put higher compression pistons, bigger cam, have some head work. In the end you won't be happy with it. Just get a 350 or 403. A stock 350 would have about same power that a built 307 would have.