Not sure why the wheelbase would be shorter on both sides if they are the same kart. But yes, you likely be lacking speed with the wheelbase being different on each side. The kart will want to pull to the shorter side pretty hard toward the end of the straight and cause considerable drag. Any kart that is bent more than 5-10mm after a wreck should definitely be checked for squareness. 30mm must have been one heck of a hit. Good thinking to check that.