I'm sure the OP got his heep running a long time ago but in a pinch I've been known to cut a bolt shorter with a cutoff wheel, dress it on a grinder and use it. Using an abrasive cutoff tool with coolant/lube (water or light oil) shouldn't affect the properties of the bolt too much, and honestly, a compromised bolt is better than no bolt at all (just don't let me catch you using Grade 2 stuff on a vehicle... anywhere! I have a story about a simple coolant leak on a Studebaker V-8 ending with me drilling out busted bolt stubs in the engine block, due to some idiot using cheap hardware store bolts...)

I do like ARP hardware though. And anti-seize. Lots and lots of anti-seize.