Very imp - Changing Header condition to Item Condition

Hi Guru's

Iam changing one header condition to item condition - manual condition. and moving the request to poduction. My doubt is like, is there any impact on exsisting open sales order, deliveries, etcs.

if they update pricing in the open sales order new condition will be activated or else its behaving same as header condition for exsisting open sales orders.

For open delievries, if we update pricing in sales order and invoice, will it take new condition or it wont chnage in invoice?

What all are impacts will have if we change? is this suggestable or not.

Thanks in advance.

Regards

Ramki