Simon1

Forged internals and an excellent tuner for the auto.

DeStonn

Def. need new internals

pascal

Might be cheaper to get an 03/04 Cobra short block than the labor and pricefor forged internals in the 3V block.
If it's not, then stroke it with forged stuff.

Rainson

it support 700HP..and good for stick...if u r getting a auto,go S/C....450 recommend max rwhp..

Nelsta21

I will say that I have heard from some guys on this forum that a single turbo on the 4.6L 3V is NOT the way to go. I hear that the twin turbo setup is a much better consideration. Unless you are going for numbers car only, but if you are going to drive the thing much you are going to have so much lag you wont ever really enjoy it. Who knows, I am no expert but I say do some research on choosing between single turbo and twin.

Caution

Well your stock block (as stated above) will take will handle 450 RWHP max -- if you start to go higher then that you're flirting with danger. Some things to consider since you want 600 RWHP --- you'll need to get forged internals to hold up the bottom end... fuel system... a stronger driveshaft... saftyloop (recommanded)... exhasut... gauges... etc. Don't forget about install as thats going to be pricy too

Haze28

I actually got a chance to talk to someone at HP and he said that the kit with their tune is very safe and will put out great numbers. If you are going this route with an automatic trans, a good torque converter with a higher stall would be recommended. I'm torn between this and a Whipple.

moosestang

The transmission! plust the rods and pistons.