4speed auto conversion Ironblock V8
 

Hello,
My mothers got a 350SL with one of the original 4speed automatics. The auto on her car has been rebuilt 2x and its still got the same problem of missing the gear alot when it down shifts from 3rd to 2nd in slow corners leaving her with reving the engine and the car going no where for like 5 seconds till it finally finds the gear.

To solve this problem we are looking at swapping the auto out and replacing it with one of the later 4speeds from the Alloy engines, 380, 500 and 560 etc. My local indy gave me a fairly cheap quote to do the job but stated that i could not use the 4speed auto and would only be able to use the 3speeds designed for the iron block engines. Is this true, i have always assumed they were interchangable? Has anyone done the swap or know of a forum thread that describes it?

Thanks for any help :)

I'm not sure if this is true but I did here a rumor that the later 3 speeds became 4 speeds with the change of a valve body. Since you apparently have a 4 speed VB this might be worth looking into further.

It is true. The bolt pattern on the block is not the same. What Roncallo says is also true. Same three speed for US market were four speed in Australia.

true, i know it from the old 6.9 s-class

Thanks for the replies. Its for the mother so having it abit slow on take off is not going to be a problem :)