Dave I have the Manley 4" kit in my motor
But Callies has a nice kit that's 4" too.

Check out the guys on LXforums.......most of them all do 392/426 kits which is the 4" crank kit

I would talk to Arrington about compression and cam suggestions. They have built a ton of boosted 3G's

Bottom line it will be purty easy to achieve your HP goals but getting that much HP to the track on radials and cal tracs will be your challenge