I have had both the .40 and .60 size. I pinned the firewalls with 1/8" dowels, and tri stocked the vertical stabs. I don't recall if I did anything to the landing gear blocks.

Be advised that the C/G location listed in the assembly manual is INCORRECT! I no longer have my manuals with the correct C/G locations. I recommend that you contact Horizon customer support for the correct C/G location.

Good Luck.