I have an SL (not a 90) with servo discs, I also have a set of twin carbs on an inlet manifold which fit the car - one of the upgrade merchants when these were new

I am considering putting a high compression, or at least a large valve head on, shouldnt be an obtrusive mod. Does anyone either have one, know of one or can advise on whether the vans all have at least larger exhaust valves (I have heard this but no real proof)