What you are describing is the clutch master cylinder. All of that stuff should bolt into the 450, including the pedal assembly.

I have no idea if the bellhousing/flywheel/clutch assembly from the 350 will work in the 450. My guess is that it would, but the best way to check would be to compare the part numbers from a 4-speed 450 and 4-speed 350 for the critical pieces.

And you need to find out if the 450 automatic crankshaft flange will take a pilot bushing.

You will almost certainly have to change the length of the driveshaft.

My 280E conversion was a piece of cake, since I had a complete euro car as a donor. I also converted my 250C to a 4-speed by chasing piece parts and that was not a big deal either.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe