I use new bolt kits from ARP. I buy one "engine bolt" kit, plus the additional kits necessary (head bolts, flexplate bolts, harmonic balancer bolt, starter bolts, carb studs, valve cover studs, etc). They can be on the pricey side, but it's worth it, IMO. They look great, the quality is excellent, and they're advertised as being 12 to 15% stronger than grade 8. You usually end up with some bolts left over that find their way in serving various purposes... like holding on my license plate:)