Hi how car you tell if it is a close block and what is the differance.

 

Take your engine apart.

If the cylinders don't have any additional supports at the mouth, it's open deck. If they have two additional, it's semi-closed deck. If there's no gap between the cylinders and the casing, it's closed deck.

 

Cross hatching on the Oil Filter housing is a quick external way to check





Mick