Date registered: Jan 2013
Vehicle: 90 350SDL, 98 S420, 97 SL500, 94 S420, past owner of W108/W112/W114/W123/W124/W126/W140 & W220 cars
Location: Tampa, FL
Mentioned: 8 Post(s)
Quoted: 607 Post(s)
Believe it or not, I have seen QuadraJet conversions. They are amazingly simple to do and can be accomplished with little more than an adapter plate and some jury rigged linkage.
I did my Holley conversion with nothing more that opening up the mounting holes on the base of the Holley and changing one piece of linkage. It was pretty much a bolt-on conversion.
JAM has very nice kits that are well engineered, but their prices seem to have gotten out of control over the years. With a Holley conversion at nearly $900, it's tough to rationalize the expense for a car that might be worth 3-4 times that.
I say grab a Holley 5200 or a QuadraJet from the junkyard, see how they might fit on your car, pick the better of the two, rebuild it, and have at it. I believe you can easily do this for under $200 on your own. I did.