Your biggest challenges are going to be finding an adapter to mount the new carb - assume it is a two-barrel, getting the choke to work right - you didn't say what the Weber's mechanism is, making the air cleaner fit, deciding what to do about the 280's emissions, and getting the linkage to work.

One of JAM's competitors makes a Weber kit, and they might be willing to help you with the bits and pieces.

If you take your time I am sure this will turn out to be a very worhwhile project.

__________________
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