These modifications- as noted- will need to be approved by the manufacturer. There are a few different ways to limit the tilt degrees. It depends on the manufacturer. There could simply be shims or spacers that are installed on the tilt rod externally and internally in front of the piston. Or it may require a new set of tilt rods (you would reuse the cylinder cans) that are slightly shorter on the end that attaches to the mast and slightly longer at the piston end of the rod to limit the tilt back. Hope this helps.