Did anyone ever actually weigh the front stock, and/or Recaros to see what they are mass wise (with base attached, since most aftermarket seats need their own Planted base anyway if you do not make up FIXED, welded-in bases for side mount shell seats)?
There are some REALLY light options out there for shell seats IF one wants to spend a good chunk of the cost of a new FiST, AND you are small in size (Sparco S-Light, under 12 lbs. each, but about $4000.00 EACH with shipping, {YES, I said $4K EACH, a virtual bargain!!
} and made for those under 180 lbs./under 6' tall).
Combine these with some light alloy side mounts and I will bet you can save a nice chunk of weight over the stockers, let alone the Recaros everyone loves so much.
Lightweight CO$T$!!