I'm trying to adapt the following:

- S4/S5 13BT Block
- JDL Manufacturing Alternator/Compressor side mount -- https://jdlmfg.com/products/a-c-side-mount-bracket
- FD Alternator (Fits JDL bracket) - Will use DC Power 180amp Alt - Can provide 5pk or 6pk pulley
- FD dimensioned idler pulley (Fits the bracket)
- FD/Rx-8 bodied compressor (JP3Motorsports supplying their AC kit for FC, an MR2 compressor has 6pk)
- FFE Trigger kit for FC

My initial thought to to purchase a Billet Rotary Store pulley, for FC, which comes in 6pk, with timing marks -- https://www.billetrotary.com.au/prod...-zpwS1ZO9oJKTs -- and adapt the rest of the system to 6pk (MR2 compressor, FD Alternator); however, I'm unable to locate a 6pk FD dimensioned idler pulley. Thoughts?

Or I could try and reconfigure the main crank hub/pulley to be some 5pk option, but I'm unsure how to approach this. Could I swap some FD or Rx-8 front crank hub/pulley with timing being unaffected on my FC, without also affect the FFE trigger wheel mounting?

JDL MFG bracket/kit


My FC block

 

If the FD idler pulley you're referring to is the one I circled in your picture below, I think you should be able to use it with either a 5 or 6 rib belt, depending on whatever other pulleys you get, since that idler pulley only contacts the smooth non-ribbed side of the belt, and it appears that it's wide enough to have contact whether you're using a 5 or 6 rib belt.