ART Pipes Hardware

[MaQG37]

I am looking to use high quality hardware to secure my ART pipes to my stock manifold. I'm going to be tightening my bolts because I have a leak somewhere and thought I'd replace my current cheap home depot stuff with good quality hardware. The size of the bolts I have found is (8) -3/8 x 1.5" Bolts
(8) -3/8 x 1.5" Nuts.

From a search, I found a user who used:

1) ARP SS bolt = 3/8-24, 1.5" length, 7/16" hex socket, (725-1500)
2) ARP SS washer = 7/16" ID, 13/16" OD, 1/8" thick (400-8509)
3) ARP SS nut = 3/8-24, 7/16" 12pt socket, (400-8302)

These are quite expensive for hardware. What is everyone else using?