Hi, I have to replace the rear wheel cylinders on my 1989 f250 , it's a custom model that was made into an ambulance when it came to Australia, it's a 5.0 litre Windsor with the c6 automatic and 10 and a 1/4 Sterling diff, Rockauto have cylinder's that are sized 2 1/2 or 3 inch can someone tell me the correct size for my old ambo, thanks for all replies.

 

Wheel cyl size is usually judged by wheel cyl bore size.. Larger size bore provides higher pressure braking.
What am I missing here?

 

Thanks for your reply, I'm not sure why there's two sizes, i guess I just want the standard size 2 1/2 but not sure why they offer two sizes ?