Strut bolts!

[Tristan Smith]

Not sure about the length, but the Nissan 240sx and 300zx rear suspension control arm bolts may also work.

[Matt93SE]

As Tristan said, look at Nissan 240SX front and/or rear suspension bolts.

the rears may not be long enough, but they are 12mm dia.
the 89-93 240SX and 89-94 Maxima strut bolts are also 12mm, and are roughly 3" length.

http://www.courtesyparts.com/240sx-p...1508_1510.html
Look at:
54302E (bolt) $4.01ea
56110B (nut) $1.97ea

I probably have a handful of those at home.

For the rear suspension links on the 240SX,
http://www.courtesyparts.com/0891294...4-p-70519.html
Bolt is $7.86ea
Nut is $1.19ea

I know I have a pile of those bolts at home since I replaced all of mine with 1/2" Gr8 and 10mm GR10.8 hardware during modifications.

If you want me to look, I'll try to measure some this week and will be happy to mail you a couple.