I'm the new guy here with my wifes 03 Lightning. I contacted the original owner and asked him about a pulley that he mentioned when I bought the truck (it was not part of the sale). He offered to sell me a new 4lb pulley kit for less than he paid for it. He suggested that I go to a local performance shop that he had dealt with in the past, to get the best out of the pulley kit. I went to the shop and spoke to the owner. He told me that I would also need a new idler pulley, and suggested a cooler set of plugs. With dyno runs and custom tunes in a new SCT tuner he was talking quite a few bucks. It turns out that the pulley kit that I got from the orig owner is a LFP Quick Change Lower Pulley kit- he says that no idler pulley is necessary, but that its a more difficult install. Any opinions ? Do I need the new plugs ? Do I need dyno tuning, or are custom tunes from one of the known Lightning vendors good enough ? I know the dyno tells all, but its a major price difference. This truck wont see the strip or be raced. My PSD has custom tunes in it and has never been on a dyno, and it runs good enough for me. Thanks for the help,

 

It's always better to go with a lager bottom pulley rather then a smaller top pulley. If you go with the top pulley it's a good idea to get the idler relocation bracket.
When you say they told you you need a new pulley.do you have a bad pulley or are they talking about the new idler pulley with bracket? (Relocation bracket helps prevent belt slip) With the larger bottom,,you shouldn't need one.
You should have cooler plugs with a 4# pulley and a new tune. Dyno or mail-order,,it's up to you.

 

Phil,
I was referring to the new idler pulley. Thanks for the rest of the advice. I'm off to the shop...........