I currently own a 1993-190E with a 2.6 liter engine. The engine has 159K miles and the head gasket is starting to seep coolant. I would like to replace it with a 1986 3 liter engine with only 70K miles from a 1986-300E. My questions are:

1. Will the 3 liter engine bolt up to my existing transmission?
Both transmissions are a 722 series type.

2. Will I have to make any modifications to the fuel or exhaust
systems? The appear to be the same.

Some help in this area is appreciated.