Shovel heads and jugs were handy to replace Pan heads with worn bronze valve seats and cylinders with no remaining overbores. Back in the proverbial day bikers used their scoots as daily riders and basic transportation. Many of us didn't bother owning cars or trucks. (I didn't until age 28.)

What mattered was reliability and low downtime. If you want to know why bikers installed Shovel top ends, look at some of the cracked, worn out Pan heads owners are spending mad cash on to restore!

 

The Shovel top end was chiefly a performance upgrade, Shovels produced a bunch more horsepower, so more bang for buck.

 

Pan exhaust "spigot" was also a constant weak point

 

No you are not right, a Pan Shovel is a Pan that has been converted to have Shovel heads, hence a Pan Shovel.
The first shovels started in 1966, the Genny Shovels were from 66 to 69, thereafter you got Cone Shovels, aka known as pimple shovels.

 

Don't forget the rare and elusive Shovster.

 

Almost as rare as the Magnum 45

Sportster top on 45” flathead cases
Seen a few in milk crates that were “ almost done”

never saw one one that ran, I suspect it wouldn’t run for long given the meager dimensions of a 45 crank pin

i could be wrong

 

You are off topic, stay with the flow, don't muddy the water.

 

Roger that!

 

Obviously you do not understand what a Pan Shovel is, it is a Pan Head 1948-1965 which has the later Shovel heads fitted.