The "crank it until it snaps off then back a quarter turn" is very old (and still good) humor, pretty sure I heard it first before these cars left the factory. The torque specs page from the library noted above is great, but does not contain the spec for the U bolts connecting the axle to the shock plate (leaf spring clamp). I have been Googling for a couple of hours now without success. If anyone knows what this should be it would be greatly appreciated.
Isn't that the "Nut, Lower shock mount to axle (Firebird)...... 60" in that '68 Pontiac Service Manual section that is referenced?