Clutch Diameter

[ianscooby]

Having a problem since a engine up grade with clutch slippage, I've been pionted in the direction of a kennedy stage 1 which I've now purchased but it looks too small, supplier says it's right??.
Anyway I do not want to take the engne out until I now it's right so can someone help with a clutch diameter for a 70 bay, standard box etc

Thanks in advance

 

[froggy]

My '71 totally standard has a 200mm clutch