Dominator 88 gearbox

My 59 99 has the AMC gearbox and the numbers match the frame and engine, so I would imagine the 88 would have been exactly the same.

By 1959 the AMC box  was fitted to 88 and 99  and the same box went into the other models too.

At the Bracebridge Factory from bike 68931 onwards all Norton Models had AMC 1 boxes fitted as standard. The exception being the International and Manx models which kept the earlier set-up until 1959.
The change-over from Laydown to AMC boxes did actually begin at Engine Numbers 68761 to 68828 but then the supply dried up and Laydown boxes had to be used once again for several more batches of singles and twins.

I have an AMC Norton type box in a pre featherbed frame that would have had a laydown box so it would seem that they are interchangeable, although I would pay attention to the dimensions of the mounting lugs as I seem to remember having to use a spacer at the bottom, but of course I dont know the history of the AMC box and what it was previously fitted to, 
Dan 

Dan......send me your gearbox number.  I have some of the earlier records.