Yup. Had similar when fitting the SRM belt and had to relieve the divider and take a bit off the outer belt guide of the big pulley.
Similar minor hassle when I replaced the SRM one with the slightly tougher kit that was sold by Manormike at Dynamo Regulators, now by someone else. Talking very small amounts, but had to be done. I think the castings are a wee bit variable, as some folk I know never had the problem.
A more serious issue was the failure of the taper on the larger, driving, pulley on my SRM one after about 20K miles. Ended up de-riveting the steel centre from the old chain's sprocket and setting it into the ali pulley's centre, machined to suit. Don't think the problem was my spindle's taper as it took the original part no problem, and then later on the replacement Dyn Reg kit.
Despite the slight hiccups, a conversion I liked well for the extra rpm it provided for running at 12v on standard windings, and for its quietness, while eliminating the risk of aluminium paste caused by a slack chain with an appetite and attitude.
