launch kit
 

What exactly is included in the Pettit launch kit? What do I need to launch my car at red line? shocks. bushings, good springs, Kazz diff. What else? should I buy the Pettit lauch kit or make my own? Thanks in advance.

Without getting into too long an explaination, there's no reason to be launching your car at redline, especially if you're running the twins still. You'd have to play with it a little but you'll probably see the best results launching around 5k give or take. However...... if you insist on winding the car up that high and launching here's a list of things most likely to break in order from most likely to least:

...if you're making 400+rwhp and launching at ~7k
clutch - you'll probably fry the clutch LONG before you start breaking real parts, which is a good thing.
diff - upgrade to the Kaaz or the Ford 8.8" if you truly need it (which you probably don't)
axles - you can go with the chromoly upgrades if you start twisting the stockers
PPF - this one is a variable, it could go first or last. depends on too many things to say for sure.

How you setup the suspension will greatly affect if/when you will start breaking things. Take a good look at what you really need before starting to upgrade parts that will serve you just fine.

pettit launch kit is the trailing arms and toe links. it helps but its not the complete package to stopping wheel hop and preventing driveline destruction :)

I haven't dyno'd in a while but I think I'm at around 350. Last year I broke my differential so I'm trying to be safe this time. My bushings are stock and have a 100k miles on them, I'm wondering if I should get the differential brace? or does the Pettit race kit include it. I don't get too much wheel hop but my car doesn't squat well at all.

Sounds like you might want to look into rx_rotary2_7's Diff brace :wiggle:
Check the GB section for that. Also, Rotaryextreme has started fab'ing their own toe links/trailing arms, so you might want to shop around for those things.

Damn! more money! when will it ever end!!!! :) I think I'll definately start w/ the diff brace.