Re tune for intake, is it a must and how long?

[sblue]

Hello all!

I'm going to be purchasing a Volant intake for my 04 F150 5.4 and just want to confirm that I will need to have my Gryphon (original style) re tuned for this? Currently running a 87 performance tune.

How much rwhp can I realistically expect from the intake with the tune?
and also of importance to me is how long to receive the updated tune?
It's been years that I've had this programmer so I can't recall the exact time frame I waited but I do know it was more than 8 weeks. Will I have to wait this length again? (not meant to be rude at all, I hope no one takes offense)

Also, it's been a few years since I've had my tuner so I forgot if I need to send it in or is an email sent out to me?

On a side note, I hardly ever switch levels on my gryphon as I'm very happy with it as is, but when I do switch to tow mode I notice that for a few days that my truck will idle really low and sometimes shut off at a light or stop sign etc.
I'm assuming once the computer re learns it stops as it's always been the case that after a few days it returns to normal.
Do I need an update or anything? I hope it's not a faulty programmer or anything?