340 cam

Well, more power is almost always guaranteed with a roller vs. flat tappet, but that gets really pricey really fast.

I would suggest the Lunati 60403 http://www.lunatipower.com/Product.aspx?id=1545&gid=287

It would be definitely streetable in your present set up and and the only machine work required would be for the recommended dual valve springs. Those valve springs would need to be changed out anyway. Needless to say, retainer to guide clearance should be checked too, but this cam doesn't have crazy high lifts which your head may not be able to use efficiently anyway.

You could also go as big as the 60404 with your gearing and torque converter, but streetablity will suffer a bit.

I hope this helps. :)