I finally got my hands on the Honda K24's intermediate shaft, which has allowed me to finally center up the engine. Once in place, I could finally confirm some ideas I've had about what tubes to add and where. I didn't plan my weekend all too well, though... I ran out of tubing, slowing down my progress big time. Eventually, though, I got the two biggest tubes I'll be adding to the car in place and fitted nice and tight. They'll make great support structures for the engine swap, and will stiffen the chassis a ton.