I tried my new belt in last night Blue. It was about 1-2 mm wider than my old one so I think the old one had just worn down. Looks to sit higher on the cluch at idle.
Did not see any improvement in top speed, still seems 3-5 mph slower, only does 45-46mph now
On the plus side my take off speed is improved and acceleration from 0-20mph is faster too.
Would like to regain my lost top end mph if I can, its bugging me now.
Did inlet manifold at same time so thats fine now. Will try it for a few days to be sure how it is.