I know this is a late reply to even the bump but it's a lot. If you're concerned about weight then get the Artec which replaces the gas skid but given the weight of the kit I'd ballpark the MC kit added about 175lbs to the truck. Shipping weight was 220lbs and there wasn't a lot that came off. If you could build a crossmember to support the fuel tank like Artec does you could shave another chunk off removing the OE gas skid I'm sure.
That said you can drop the truck on this system without a worry. Mine is scratched to hell but still straight as can be.