a few years back i tried to run the center squirters part # 4224 and never liked them. they had a dead spot i could never fix. since then i`ve ran two 750`s part # 6109 with no complaints. my motor is a BB chevy 468 with a lunati roller 680/700 lift. all 8 jets are no. 74`s. this is in a tx-19 hull and b impeller. turns 5800 at wot.