DEV-3hl kit plus more

[Paddyboy]

Hey guys
i own an el XR6 manual and i want more power out of it.
right now i have genie extractors and 2.5 inch exhaust.
im interested in your dev-3hl kit. I noticed there is a big price difference from dev-3hl to your dev-4 kit, i know its because of the heads and labour.
i have a budget of about 3500 and the dev3hl would cost me about 2000 coz i already have the extractors and exhaust so my question is what else can you do on top the dev3hl to get more power out my beast?