Gti6 Servo Clearence

[Rob Turbo 3]

How much clearence is there between the head/timing belt cover and the brake servo on a 205?

 

The servo from my 205 has seen better days, mainly just rusty and generally tatty on the outside and I have a servo from a 406 coupe that's the same diameter but thicker, with it being newer and bigger I'd like to use it, plus with it being thicker the master cylinder would end up higher with it coming out of the bulkhead at an angle, so might sort any clearence issues in that department?