Hi Jazzy,
That is the neatest idea I have seen for increasing back pressure with the Slimline pitts

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I'm hoping not to have to do it on my extra 300 (Goldberg BIY), the difference there is that I have the long extensions (9") on mine which will tend to increase back pressure. I've run about 6 tanks through the G91 ST and it seems fine, but now I know how I will increase the back pressur if needed.
Thanks,
Pete