So I'm getting ready to pull the switch on a set of Caltracs, split mono leafs, shackles, pads, bushings, etc... Basically I plan to replace all my rear leaf spring suspension. I'll be talking to Calvert racing tomorrow about this but in the mean time I thought I would ask here. For my 78 with GM 10 bolt diff. Staggered shocks. My questions are, my OE spring/shock mount brackets had tee bolts and small diameter u-bolts. I didn't measure but they look like 3/8ths diameter. Possibly 7/16ths. I'm not great with eye balling sizes, but I know they aren't 1/2". The replacement u-bolts I'm looking at from Caltrac are 1/2inch. Looks like thats the only diameter they sell. Any problems with drilling out my mounts to accept the 1/2inch u-bolts? Also any thoughts on swapping out the inside tee bolts and installing u-bolts so that I would have 4 u-bolts as opposed to 2? I'm thinking 4, 1/2" dia U-bolts for 3" axle tube and 6 inches long? Does that sound right?