hey kiddies,
i followed this DIY mod last night and had ZERO problems. bolts were just under $16 at Lowes. the thrust flange bearings were reasonably priced at Lowes, but the carriage bolts were about 4x the price compared to McMasters or Boltdepot, but you have to factor in shipping and time. certainly less than you'll pay ordering from from one of the manufacturers.
couple clarifications:
grade 8.8 is the strongest designation i found online for a bolt with a 1.25 fine thread pitch. someone please correct me if they find grade 10.9 in fine thread metric in an M12 bolt of any kind (carriage or hex).
you must, MUST, M U S T, chase the threads before installing, and chase them twice. blow them out in between and spray it down heavily with penetrating liquid or cutting oil propellent. even after chasing threads, it was still very slow in torquing it down. take your time and do it properly. a quick inspection in the pilot hole should show you that the years of use have mostly obliterated the threads. you really are re-cutting them.
my subframe was aligned and i didn't need to loosen anything. just jacked the rear for jack stands and crawled under last night with an LED flashlight. it was probably in the 30's.
result: rear hooks up solidly. a very good $16 mod.
DIY link: NASIOC
http://forums.nasioc.com/forums/showthr ... ?t=2183600
Install instructions: NASIOC
http://forums.nasioc.com/forums/showthr ... ?t=1752267
be careful out there, and as always, i assume or accept no responsibility or liability for your actions in modifying your car. please know what you are doing or ask questions. be safe!