389-p-8 or 159-p-8.. anyone familiar with these?

[athenashee]

i have a pair of 34mm flatside mikunis and am changing the needle jet from a 389-q-2 to a 389-p-8 and was wondering if i also have to change the needles to a different size? if so how to i determine what size of needle to get. also would anyone no if 159-p-8 would work as aposed to a 389-p-8. the place i ordered them online and will not return them there a little bit shorter than the 389's but i did order the 389's because i figure they wont work. also does anyone kno much about needle jets? i have 392cc athena big bore cylinders. cpi big bore pipes and pods and from 1/4 to 3/4 it had absolutley no power and bogged down so im going from a 389q2 to a 389p8. Does that seem like to big of a change or not enough? not familiar with needles and jets. it currently has 5fp17 needles and have no clue where the heck i can find what size the 389p8 takes for needles. thanks for the input in advance!

[camatv]

your best bet would be to call SUDCO and talk to them they are great with carbs..