Club 80-90 Forums

Will a 2.1 engine be OK with a 4 speed gearbox re MPG etc , existing unit 1.9 Watercooled DF engine code

Should be fine. Top gear is almost the same between most of the 4- and 5-speed boxes - look at the RPM at 70mph for instance in this table.

You need to find the code on your gearbox to see what you have. It seems the vans shipped out to the usa with 2.1 engines had 4 speed boxes more so than the european market, similar ratios as the gearbox fitted to later vans with 1.9 engines in europe.