Engine fasteners?
Kits.... PM whitepunkonnitro here..... I bet he can fix you up with all sorts of stock fasteners for things like timing covers and pans and valve covers and cam retainers, etc. (Even used head bolts if you are comfortable with those.) The head bolts is one place I would consider an ARP set as you can't know 100% for sure if used stock ones have any stretch or not.
What are you doing for rods? If picking up stock ones and having them re-conditioned and adding ARP bolts is your thought, then look into some SCAT rods; all new, all the rods studs/nuts, and all balanced rod-to-rod and end-to-end with the numbers on the box. Will probably cost < $100 more than a set of stock rods re-conditioned with ARP bolts and will be balanced as noted.