Paul thanks for the reply, but I didn't mean 600 inches. I meant to say 600 ponies. When I said stroker I meant something in the 500-540 cu. in. range. I don't really know Ford combo's that well. It seems a 513 seems to be popular. I already have a stout shortblock 460 that is just short one piston, but I can't get any real info on compression or bore size as it is in storage out of state at the moment. I got some heads in a seperate deal on the cheap when the machine shop condemned my first set for multiple cracks. This project got put on the back burner some years ago, but now I am thinking about putting it together if for no other reason than to sell it and free up some space in a buddy's garage.