In terms of getting pulleys for an '03 Lightning, is an Underdrive kit what I'm looking for? .. I've never upgraded them on any truck I've owned so I'm not too familiar with going about shopping for them.

Mike

 

Troyer told me I couldn't run a underdrive pulley kit with a Lightning set up.

Phil

 

Like Phil stated already, you cannot run an underdrive pulley system for a N/A F-150 on your Lighting, I believe you are looking for something like this

http://www.lightningforceperformance...3ead4ad89249e6

there are several vendors that offer these so decide which vendor is right for you but if you choose rpmoutlet you've been warned to avoid them

 

Without a tune, should I go with the 4# or 6# ?

 

You should not go with any pulley without a tune!
You could probably go with a 2# but your still taking a chance without having your tune at least checked.

With a 4# you need a tune and with a 6# you need a tune and an upgraded MAF.

Phil

 

Ah, alright. I see now. I suppose I'll add a tune to my list