RPM clueless

nm9stheham said

I recall these looked different than the 4spd OD pictured but certianly can't swear to that anymore. (But the AL box looks right...)

Click to expand...

I know of no visual way to tell an OD from a 4 speed externally, other than the shifter. If it's out of a car, IE used parts, it's even possible someone wrongly flipped the lever upside down.

Only way I know of EASILY telling on a used piece is to put it into OD or "3rd gear" as if it's a 4 speed, that is, rotate the front shaft CLOCKWISE

Then rotate the input shaft one turn, and watch the output

Less than 1 turn means a 4 speed, more than one turn means an OD