I bought mine used, so I don't know if it came with a bolt kit or not. I'm not sure if they use the same bolts, some go thru and won't be a problem but others don't. I bought all new Grade 8 bolts for mine (actually I think I used socket head bolts for easier access up top while its in the car and they are grade 8 anyway) but the bell has beenout of the car so long, I don't remember where the bolts are to be able to measure them. I'm thinking 1 1/4" but I'm not sure.
On a side note, since you're in the state, are you coming to Norman this weekend for the FordFE.com Spring Nostalgia Nationals? We'll have probably over a dozen 427 Cammers, expecting 30-40 original Thunderbolts and who knows how many clones, some Shelbys (including an original '66 427 Cobra), there will be Nostalgia Super Stock and Nostalgia Muscle Car class racing with about 30 cars in each class. Racing starts Saturday at Thunder Valley Raceway Park, gates open at 8 am. Saturday night is a banquet featureing Phil Bonner, Hubert Platt, Len Richter (all factory Ford drivers from the 60's), Bill Holbrook (Ford Engineer from Ford's "X" garage which I guess is the predicessor to SVO/SVT/FRT), Jim "Hammer" Mason (of Dearborn Steel Tubing, they built the original T-bolts) and others. On Sunday the car show will move up to the Lloyd Noble parking lot on OU's campus, setup starts at 9 am and awards will be at 2pm with the show shutting down at 5 pm or when people start clearing out.