Chad, I had similar problems when I replaced the clutch last November on my '57 3/4 ton with a 235 and an SM420. I didn't think that I would ever get it out...or back in. Mine came with the heavy duty 11" clutch and pressure plate. My hunch is that you might have the same. I bet the smaller 10" one would have more wiggle room, but the 11" barely fit.
I tried different ways...pressure plate first, clutch first, etc. and finally got it out. Try to remember how you got it out because you'll need to do the reverse to get it back in.
I did mine on my back on the garage floor. It would have been much easier with a lift.
I scraped up the back of my hands pretty well and finally got smart and put on a pair of gloves.
I'm not familiar with the underneath of a '53 GMC, but thought that I would share because I had the same frustrating experience with my '57 and had to get the sequence just right to get it in and out.
I had purchased a 10" clutch not knowing that I had an 11". The 11" is harder to find. I was lucky that my local O'Reilly had an 11" in stock. It wasn't listed for my truck. The part number is K5473-01.
Good luck,
Matt
