I fully admit though that I don't see why the mechanical upgrades are not available as an "ARP4" pack, though, with all other options and spec available from the regular options list. That would be ideal.
I bet that AR P4 bits will make into standard +4s by mid 2016.
And I bet they won't - with the exception of the five-link rear axle.
Why? Because the (standard) Plus Four is for people who don't want a hugely challenging drive. Enough torque to be more than capable, but not so much power as to require huge circumspection. If you want more involvement you buy a 4/4 and if you want a surfeit of power over chassis limits you buy a 3.7 Roadster. All three trad types are great in their individual way. But your 'typical' Plus Four purchaser is not looking for 225 of Cosworth's finest horses... even though many on TM may be
