I have them both in my garage now, and when comparing the sizes they are almost identical. You might almost say the JL race pipes is a copy of Jollymoto. The tuned length is about 10mm longer on JL vs Jolly, and the added length seems to come from baffle cone being a bit less steep, therefor longer as the belly diameter is the same (108mm)
The center pipe of the JL though, is way lower than center of Jollymoto. That's an issue if you use a 18 inch front wheel and have the front lowered 1 inch as I have.
I have not dynode the JL yet, but since they are close to identical as jollymoto, they will kick ass for sure. NO pipes sold new today that I know of (except WTF maybe, I have not tested them), and certainly no old school look pipes can compare to the powerband jollymoto produces (thus also JL race)
BUT...as said: Pipes like DENCO is better in mid range than Jollymoto. Maybe the JL pipes will be a bit stronger there, and that is a good thing. Adding 3 rwhp at 5000 rpm, and give away 5 rwhp at peak power 8-8500 rpm, is not a bad idea.
And yes....JL race is improved compared to jollymoto regarding strength (rear mountings)
Jim at fastfromthepast sells them Barry, the JL.
I think I can say I recommend them, even if I have not dynoed them yet. And they look good in polished stainless as well. Go for it, Saint