Sounds like a really cool car and I like being as true as possible to nostalgia stuff. I believe the fastest I have heard of was a member here that ran high 8's on SS springs (Red '64 B body?). I don't believe they lasted a long time at that power level and might not have been the most consistent, but he made passes and a good number of them. The car tended to wheelstand so while I don't know if the 60 foot was great for that ET, it certainly got moving in a hurry.
Remember that car. Red and white, think he was from Kansas if i remember right.
The guy who bought mine went on to run 9.62 at 140 with it. Still has it, still on the same leafs. Thats a solid 700 horse at 3220 race weight its currently at. I bet it would still work with more steam.