Bolt ?

What grade bolt do you recommend to bolt the air bags to the bag mounts?  Is grade 5 ok or should I use grade 8? Thanks

you should always use grade 8 hardware. Grade 5 stuff ain't afe. It's not rated as high weight of grade 8.

As a general statement, to keep novice builders out of trouble, low mazda is right. But realisticaly, there is no reason to use a high grade bolt to mount a bag. Grade 5 is fine in that situation.

i've had grade 5 bolts break on the front f a mazda. I won't use grade 5 anything in the suspension period.

If the bag plates stay pretty aligned like a bag over axle set up then it should be fine. If the bag sees a pretty big misalignment like on the front of a mazda the bolts will see a lot more shear load and grade 8 is the best option. 

^^^ I can agree with that. The way that I set up my front ends the bag doesn't see those crazy angles, so I've never had the issue. Also, properly tightening the bolts play a HUGE role in breakage.