put a 390 in a 66

what all would i have to do to a 66 coupe to take out the 302 and swap in a 390 and how much would that cost-its bored to a 428 and has power steering with stock exhaust manifolds-thanks

Unlike the 67-70 stangs putting the big block in a 66 is a lot more work which is going to involve trimming the shock towers so there is room for the header/exhuast manifolds.