3400lbs...??? No chance. Maybe the slant6/3spd/7 1/4" blank fendertag car weighed that...

I'd say you're somewhere around 3600-3800lbs stock, unless its an optioned out big block car. My A66 low-option 340/4 speed 70 Challenger... generally lighter than a 71, and certainly lighter than a ragtop weighed 3550 without me. Small block Mopars weigh around 575-600lbs? So what do the new hemi's weigh...??? (less, i assume) and the tranny? then just do some math...

Also keep in mind that if you plan on upgrading the rollers, suspension, brakes, chassis, stereo, sound deadener, etc, that all adds up. I assume you want to guess what this thing will weigh once its finished.