Yes indeed, its a big engine. Did the 300 SL already have brake discs or is that an upgrade on the pictures chassis?

I heard the rear axle of the 190 SL was rather weak and would not cope well with additional power and torque. Do the ponton six have a different axle? The idea you have is a nice one. With a developed M110, three side draft webers etc you could end up in the same range of performance as the Jaguar E Types... the aspect of the twin cam M110 could be worked so that it looks of the era. I read people were increasing the capacity of later MB 6 cylinders by fitting Diesel crankshafts. a 3.8L Twin cam M110 in a 190 SL would be fun!