Hi Rod, I would be interested in the 250L pipe specs also if you dont mind letting us have them. I have built some L pipes for someone that were for the seel barrels, but unfortunately when he also tried them with standard L barrels although they gave good peak power they had a big hole in the mid range power . Would be interested in comparing the specs of the two different pipes to maybe get an idea as to why the seel ones gave such poor mid range power. It would be interesting in how different the porting was on the seel barrels by comparison to the standard L barrels but unfortunately it wasnt my bike so I never got to see them. Hence the only info I have is the seel pipe spec , but would be intersted in the L pipe spec for comparison.