haha... I think growing up in a Hokkien only family I can safely say Ah Chek is younger... Ah Pek is old man.. Ah Chek is older uncle..
But then some guys here have phD in Hokkientology so I might stand corrected..
So I am Ah Chek instead of Ah Pek...
By the way, some older hokkien families will have the children call their fathers Ah Chek, not Ah Pa... I only found out it has got to do with fortune teller saying that in doing so will bring "peace and good fortune" to the child cos' their Ba Zi clashed... (maybe wrong, only learn this from older Ah peks). I grew up calling my dad Ah Chek......