I swapped out to the new 3/8 unit...and I am probably going to put the 5/16 unit back into my tank...Reason being for the same problem you are having...Plus I figure since the rest of the hard line from the tank to the engine bay is factory....a 3/8" in the tank is useless...like shoving a tennis ball through a firehose....it could eventually get through but with great resistance.