I have never tried this. So If I want to go to 12.3" (most of the proline body has this wheelbase). I would need to extend the wheelbase by approximately 1.5" (38mm). Do I extend all links (upper and lower) by the same length? RC4WD has the different sized extenders for $10.99/4 pack.
25mm-098-Internally-Threaded-Aluminum-Link-Black-4_p