Never been able to get a reply from Harpers either. Tough to know then now, as it seems I'd need to remove at least one silencer to make any discernible difference.

Originally Posted By Malcolm T
It didn't make much difference at all.

Mine was a Heart of England (John Worrall) sports system, which appeared to be normal system with a straight through tailpipe.

I posted the link to Harpers because John Worrall no longer does exhausts and the Harpers drawings are very helpful in identification of components