If your kids outgrow baby diapers but still need diapers then there's Youth Diapers available such as Tranquility Youth Diapers and Attends Youth Diapers.
Pampers also makes a size 8 pampers swaddlers diaper that fits most kids up to around 10 to 13 years old.
There's also another size 8 diaper called Boundless that is made for older kids who still need diapers.
Pampers Cruisers size 7 diapers will fit most average size 8 year old boys without any issues.
If the 8 year old boy will not fit in the Pampers Cruisers size 7 diaper then he should fit into Pampers Swaddlers size 8 diapers.
Pampers Swaddlers makes a size 8 diaper now that fits most kids up to around 10 to 13 years old without any issues.
If the 8 year old boy won't fit into the size 8 diapers or won't wear them then they could fit into a youth sized diaper.
You can buy Youth disposable tape on diapers online that fit kids that outgrow baby diapers and they work much better than Goodnites or other bed wetting pull ups.
Tranquility Youth Diapers and Attends Youth diapers are good Youth diapers for 8 year olds and kids who may not fit in most toddler diapers.
But an 8 year old boy of average size should fit into a size 7 pampers diaper.
My 8 year old son who wets the bed wears a size 7 Gentle Steps diaper that is a good absorbent diaper and cheaper than pampers cruisers diapers.
You can buy the size 7 gentle steps diapers at dollar general for around $6.00 a pack for 20 diapers.