I've got a 4 speed on my '53 3/4 ton. I got two 6" carriage bolts like someone on this site told me not two weeks ago. On the left side there was enough clearance to use the whole bolt. On the Right side though I had to cut the carriage bolt only about an inch longer than the bolt (screw cap) that came out because part of the transmission protrudes out far enough behind the hole to block anything longer. This was enough though as I only screwed the carriage bolt in four threads. The longer left side gave me the stability I needed after I ran out of bolt on the right side (of course, I was removing). Good luck.
