Hi I'm getting mix up when going to buy a carb float needle for my Vespa T5 with malossi 172. I see there's 3.5, 4.5 and 5.5 spring loaded. 3.5 and 4.5 say they are for the T5 on some sites. So with one do I get. I read about the 5.5 you have to drill the carb float chamber.