i took a 1/8-1/4 do it mold and drilled it and filed to fit 635's and it works great and the thing i like about it is i can still use 575's in it also....just drill out the eyelet hole to the size you need and file out the hook shank gap a lil and you will be ready to go....if you do it right you will still be able to use 575's in it also....tools i used....cordless drill,1/8 drill bit and dremel with a cutting disc