I had borrowed an engine picker in order to pull the engine and take it back to the machine shop, but the machinist is away until September. (The joys of dealing with a rural ''Mom and Pop'' small business)
My buddy had a look at my engine mounts when he dropped off the picker, and said that perhaps we could cure both the firewall and floorboard problems by just mounting the engine and trans a couple of inches lower. I think he may be right... there's a lot of clearance between the oil pan and cross-member.
Now that I have removed the cab again, I can also see that the trans yoke is a couple of inches higher than the driveshaft center bearing. It's amazing what a fresh perspective can do.
I found a MUCH better fix for my by-pass hose. I had been using the stock bypass hose for a 1979 C20 with a 454, but it didn't work real well with the Air Gap intake. I had to cut it up a bit, and then use a uni-coil to prevent it from kinking. Not real elegant, I thought.
So during the current round of ''Intake Removal'', I thought I'd try a different approach.
NAPA Temp Control (Everco) #H4878 is a 1/2'' MPT x 3/4'' hose nipple with a built-in 45°. At first glance, I thought it might be too long, but it turned out to be darn near perfect!
Just add a short peice of 3/4'' silicone heater hose, and we're good to go!