so i have two different valve spring compressor tools both of which are not meant for a b20b. b18a1guy posted one that he said works called "Schley Universal Overhead Valve Spring Compressor 91400" but i didnt have the money for one so i kept tryin different ways to make the ones i had work. i made a few "adaptors" for the c clamp looking one but they kept breaking so i tried a socket....nothing.. couldnt get my fingers down far enough to do anything. long story short i found that if you take a good sized socket and put a ziploc bag over it and you put the keepers in the retainer first compress the whole bunch and when you take it off.....bam!! keepers installed woot!! and all for a $12 c clmap valve compressor tool and some ziploc bags

Sounds like a good trick if you don't want to invest in a valve spring compressor.