Thanks Roelof. I checked the crank timing last night and it's only open for 205 degrees of the rotation, which is common. I'm going to remove .75mm from the opening, and closing, open the exhaust port a little on each side, and a few other things. I will Take pictures of the process and post a video of it running after I finish.
Originally Posted by
Roelof
If it will outperform can only be seen by giving it a try. I think the REX will give more torque due the bore/stroke differences with the NS15
I think you have to look at the mounting differences. If it is needed into a small block mounting it will be more difficult to mount the REX