Have a 1973 electronic distributor that came out a 413 motorhome ( industrial motor ). # on Dist. is 3656839 . Question is how well will it work in a RB . Know it will work ,MH had 4.56 gears .TIA

If it checks good on the shaft to housing clearances I would shorten up the mechanical advance some (it will have a number stamp on the bottom of the advance plate which will be the amount of advance in distributor degrees so if it is stamp 12 it will have 24 crankshaft degrees at full advance) I like to have between 12 and 20 degrees at idle with no advance with 34 degrees max advance so use that and figure out what you want
Measure the slot length and subtract the pin diameter to see how long the travel is and then divide the length by the degrees to get how much each degree is in thousands of a inch, if .300 long with 24 degrees that would be .0125 per degree
IHTHs

If the shaft/bushing (radial) side play is very minimal it'll be fine, as Cab said you can dial in the slots, you would set the initial/total/spring combo then plug in/adj the can (if used) IN ORDER. Speedway mtrs has a flat shim kit for $9.95 for the 1/2" dia dist lower shaft & reduce the axial play to .005"

Check to see if that distributor is a DC/MP piece ..... I got two motors with that piece on them ... one with the wiring and the box

If it was a true industrial engine, it probably won’t work at all. Industrials used gear to gear cam timing. Reverse rotating cam requires odd distributor/ intermediate gear. Normal cam rotation drives the intermediate shaft down towards the bushing. Reverse rotation cam tries to drive the intermediate up towards the distributor. Those distributors are designed to hold the gear in position, and are not standard dimensions.

TRUE INDUSTRIAL... I don’t know but the ones I’ve seen in the motor homes is a diff distributor drive gear

looks like a reg. electronic distributor motor had the big water pump and different heads and big ex. manifolds one of which was broke