Hi all, I'm new to the forum and was hoping I could get some help. I have a 64 with the original 4.11 12-bolt Posi rear-end, a Hurst 4-spd racing transmission, and a brand new GM Performance crate 350/300 motor and 215/65/15 tires. Question 1: what is a "safe" max cruising speed right now without over-revving that new motor (which I have been diligently breaking in over about 500 miles now)? Question 2: when I get the rear axle re-done (which will happen within the next 6 months or so), what ratio would you recommend to provide easy highway cruising but still have some punch off the line when I feel frisky? This is assuming no other changes to the transmission, motor, tire size, etc. I would appreciate any guidance on this from you experts out there.