I converted an S2 chassis to mostly S1 spec. I didn’t change the end flanges and just used S2 coolant pipes. Not too much to do really:
- weld on nuts for the three different throttle positions,
- tabs for the seat belt braces,
- bend up the S2 lower flange and weld it to chassis for the front floor.
- fabricate toe boxes to cover the lower a-arm mount (leave enough space for the arm to clear!),
- remove the S2 side mounting flanges
- etc.