Picked up a 1/4" drive, flex head ratchet, but a long handle version. For my bellhousing to T5 adapter, I installed it with some 12 point 3/8" bolts at the upper two holes. I had to make a new adapter and instead of removing the clutch assembly, I was able to barely fit my hand in there to remove and install the two 12 points. But how to tighten them? I thought I needed the 1/4" drive but found my 3/8" drive, long handle flex head did just fine. In the future, I'll have multiple choices for install and removal. Discovered I needed more 12 point sockets, so I added a 1/4" drive set to the home box.
