does anyone know if the alpha crf 3 port piston / sleeve is the same as the alpha abi 3 port piston/ sleeve? I took a look in my 1 gallon old alpha abi and found the piston is missing a piece out of it . the alpha abi piston/ sleeve is significantly more expensive so I'm hoping for a cheaper fix . If not I'm wondering if I could grind the chipped part of the bottom of the piston smooth and just run it?