The approximate position of Our Lord’s Head… at the moment of His death… is recorded in just one of the four Gospels. St. John tells us…
“When Jesus had taken the wine, He said, “It is finished.” And bowing His Head, He handed over the spirit.” (John 19:30).
But it doesn’t specify Our Lord’s Head… either to the right or to the left. It just tells us, that He bowed His Head. Most crucifixes do seem to incline Jesus’ Head to the right… but I think either way is appropriate. Like the others who have replies… I’ve seen a couple different variations.
Hope this helps. God bless.