Looked into the T5m to SC5m parts conversion a little more. There seems to be some errors in the Associated parts spreadsheet. Lots of B5 only parts (like arms and shock towers) are listed as being compatible with the SC5m. Near as I can tell, these are the parts needed for a conversion (excluding wheels and body):
71025 SC5M Chassis
71027 SC5M Chassis Cradle
71028 SC5M Side Guards
71029 SC5M Front Bumper
71030 SC5M Rear Bumper
71031 SC5M Body Mounts
71032 M2.5 x 14mm SHCS
71033 SC5M Front Axle
71037 M3 x 45mm BHCS
And maybe these screws:
25204 M3 x 16mm Flat Head Hex Screw
89205 M3 x 26mm BHC Screw
89453 3 x 35mm BHC Screw
Not sure why the front axle would be different than the T5m.
71034 Clamping Wheel Hex, 6.0mm - is also listed, but I assume that is an upgrade.