[Aussie Mike]

390lbs sounds about right for the LS1. The crate motor comes with everything except the starter and alternator (Air conditioning? We don't need no stinking air conditioning).

I'm putting the LS1 in my Classic Revival and expect the whole thing to weigh in @ around 2200lbs (possibly less). Not sure how this will affect the weight bias but light weight is good regardless. GT40s and most mid engine sports cars have a more rearward weight bias than a Cobra and this doesn't seem to hurt their performance.

680lbs, from memory that's about the weight of an iron head BB Chev with no accessories. It would hurt a lot if you dropped one on your toe. Remember it's easier to put HP in than it is to take weight out.

Guys down here are getting a very drivable 430HP out of the LS1 with only a change of cam, springs & retainers, good headers and a Motec ECU (all on a stock botom end). With a change of connecting rods and some head work they are getting nearly 500HP. That's 1.25 HP per pound out of the engine without even looking at a blower or turbo.

All this is probably irelevant when it comes to a Cobra unless you are a serious racer. The Viper V10 is going to have a whole lot more "WOW" value when you open the hood.

Cheers