[evilokc]

its a new model quickfuel hotrod series carb. I believe the part number is hr-580-vs. they have 4 mixture screws. one on each corner. it also has a traditional singe idle speed screw. the truck surges and struggles at constant throttle which is a sign that the jets are off. i did the vacuum test to see what size power valve i needed and then pulled the metering block to see what was in it. the factory jets are 66 but it has 64s in it now. holley tech said the carb is good size for the motor but since its on the small side needs bigger jets. they suggested i try 72s. the power valve IS the size they suggested. i guess what I'm asking and I'm sorry if this was answered and went over my head. will the known problem of small jets be more apparent once the mixture is leaned out?