there is alot of difference between the 2 engines.. as you already know one of them is a gsr and the other is a type r.. we'll start with the basic's the type r has a different cast head based off the b16 head with better valvetrain, valves, cams, and very mild hand port job from the factory, the type r bottom end has some mods done to the crank to hold revs better, the pistons are coated and yield more compression, the rods are stronger and ment for the high revs, the throttle body is bigger, intake manifold matchs the throttle body, the type r has a stock lsd transmission, the gear ratio on type r's are very short and good for track/all motor so it can redline quicker and get through the gears.. the water and oil pump is the same as the type r im pretty sure correct me if im wrong, gsr redline is 8200, type r is 9000, if you have the money for a type r i would get one.. if now just get a gsr build the bottom end, get a b16 head build that up, and get a b16 tranny with a type r lsd.. and make a better engine then the type r with all aftermarket parts .. ive seen poor mans type r's run 12's all day all motor