My Valve Spring Compressor - Heads On/In Car

That is brilliant! Did it get the wiggles on the ratchet end when you used the extension? If it did, it wouldn't be hard to make a brace that would slide on the shaft in that situation. Just run the extension thru a hole in the slide bracket that rests across the rails where the valve cover bolts on. If it doesn't wiggle, no need! :)