I have a shop in Great Bend Kansas where we do some oilfield stuff. cement floor in the shop, no gravel in the yard. So I send up a 4wd JCB forklift. Farkin mast is too tall to go through the 10ft doors. Can't find an all wheel drive forklift with a short mast to buy, and a replacement mast costs more than the lift. Is there a shop somewhere that can chop the mast off so it'll be short enough to go in and out of the shop? It only needs to go 8ft high at the most.
I will bet you that raising the hieght of your doorway would be cheaper than getting the mast shortened.
Even if you could cut the mast rails off and reweld them, you would also have to shorten the hydraulic cylinder (s) to match. I've run into this problem in the past. One of the beat-counters ordered a new forklift without realizing it wouldn't fit under any of the doors in the area. We ended up buying a whole new "lo-pro" mast assembly from the dealer. Actually I think we traded them our standard 12ft mast for an 8ft low-pro and paid the difference. :beatsme