umazk99:
I have seen this question asked before on this site and based on that, I predict a wide variety of responses of which one is certain to be Fastenal's intercompany shipping system which I have personally used before on some large items. They require you to build a pallet as I recall.
My purpose in responding is not to give you the name of a shipper. Rather, I simply ask you to consider going to a kart shop or some small business that will ship enough to have a shipping account with some LTL carrier and if at all possible, have extra kart boxes handy or be able to build you a box. Shipping a chassis, unless you are set up for it, can be quite a bit more involved than one might think. Paying a shop a few bucks to mess with this might be worthwhile.
Lastly, if memory serves me correctly, the range of cost that past posts indicated was anywhere from $100 to $150 (prior to Covid). I have a friend who works for company with a shipping account and I think he said he could ship chassis for around $85 (all figures were prior to Covid which seems to be driving the cost up on everything). My recent experience shipping smaller, but heavier items is that $1.00 per pound will be tough to beat.
Good luck!
CMac