Ok, so I am planning to install a 3" body lift within the next few weeks on my 2002 Trailblazer. I have a custom machined steering shaft extension sitting in the garage, as well as front and rear bumper relocation brackets. I am getting the lift blocks from Zone. I plan to get the longer bolts ordered from fastenal, but I am looking for opinions regarding the bolt strength before I order. There are 12 mounts. Ten are equal in length, but the front two are 2" longer. I intend to get the ten in a grade 8, but I am considering getting grade 5(class8.8) bolts for the front two mounts. I am not one to compromise safety for savings, but the grade 5 bolts in that length are $6 as opposed to $20. I haven't done the math but the way I see it, those two bolts are responsible for ~17% of the holding force for a 1,500# body and have a combined tensile strength of 10,000#(at grade5). Not sure if those numbers are accurate, but if the other 10 bolts used are grade 8, there shouldn't be any need to double my bill at fastenal. Thoughts?

 

If the factory ones are grade 5 then replace them with grade 5. If they're grade 8 from the factory, replace them with grade 8. No such thing as overkill when it comes to safety. Chances are the 5's will hold perfectly fine, but why take that chance? Work an extra shift if it hurts the wallet too much.

 

I think you'd be okay with the 2 Grade 5's considering you'll still have 10 Grade 8's holding everything together.

I would feel more comfortable with doubling my bill at fastenal though...

 

Yeah, pretty much figured I was splitting hairs over a few bucks. If I really feel the extra cost affects me, I can always cook at home a couple more nights next week.

 

I'd find someplace other than fastenal. We have a local bolt supply shop that blows them out of the water with pricing. Matter of fact last I heard they were thinking about closing shop cause they can't get any business with their over priced stuff.

 

I once ordered a bunch of hardware from them for my other project. It took forever and when some, not all, of it finally showed up it was all wrong. Went to a local place called Facca and got everything I needed for a fraction of the cost. Fastenal sucks.