All N-Frame barrel threads are the same so it should work. The "crush" fit is a non-issue. In any barrel swap, the thread must be timed in order to get the front sight correctly aligned. Ditto for adjusting the B/C gap. That said, unless you have the special tools and knowledge to do this job, just selling your existing 29 and buying an 8 3/8" model is probably the best way to go-as previously mentioned.