I Need Help With Crankshaft Nut

[dpcd67]

Rebuilding my RMC 56788. Installing front cover, I noticed that the nut only engages with 5 threads, leaving 3 not on the shaft.
Here are the numbers:
Crankshaft end play is set IAW the TM.
I have 1.9 inches length from the gear to the end of the threads. I have another crankshaft and it has the same length.
The spacer is .483 thick.
The oil slinger is .040.
The pulley is one inch thick.
The nut is .500 thick.
Add all that up and you get .123 more than the 1.9 inches that it all goes on.
I am missing something but i don't know what.
All the previous L134s I built had cranking pin type nuts so you don't see how many threads it engages.
Any insights?

[dpcd67]

Update; I inspected a friend's M38 this afternoon; his engine is original to his jeep and has not been rebuilt. It has the nut with two threads forward of the crankshaft threads.
So, I see that my situation must be ok; I will proceed with assembly.