Dope stashed in order for engine part (3,3)
I believe the answer is:
big end
'engine part' is the definition.
(I've seen this before)
'dope stashed in order' is the wordplay.
'dope' becomes 'gen' (I've seen this in other clues).
'stashed in' is an insertion indicator.
'order' becomes 'bid' (I've seen this before).
'gen' inserted into 'bid' is 'BIG END'.
'for' is the link.
(Other definitions for big end that I've seen before include "favoured by Lilliputian rebels" , "favoured by Blefuscudians" , "Important part of the connecting rod in an internal-combustion engine" , "Dramatic finale" , "Part of car engine's connecting rod" .)