I used 1/4 inch air brake line for the transfer port it is stiffer than water line tubeing .I did a test fit and it crushed down and conformed to the parts so I use it and seems to be fine. As for the valve all I did is remove the filter that's it.it 50 degrees in my basement so power wise it seems ok for 30 feet shooting it seems to have as much power as my 2100 . I have went through two refills of gas ,I hope the barrel brakes in better than it is . It's accuracy is ok not steller . Group's 3/8 to 7/16 at 30. I have 2100,880 and a 397 that can rip just one clover leaf at that range.