Leaner needles for Tm 34

[Tz250racer]

Hi,the needles on my Tm34 are 5FP17.I need a leaner needle.Sudco emailed me a list of leaner needles and one on the list was a 5dp7 but this needle is 4mm shorter the mine.Do you guys have a chart that could help me out to get what I need?.Thanks