Having extended the same crane your about to find out the hook can’t extend past the front wheels or it tips over, also that top steel tube will bend under the weight. Solutions, get some SHS tube that slots inside the black bar that goes to the hook, drill a hole for the pin to go through and slot the SHS inside the top bar. It’ll stiffen up the top bar so it doesn’t buckle. Use the same length of SHS to slot inside the bottom legs so they that stick past the hook, reuse your existing wheels on the extended legs. Ideally weld the inner tube to the existing leg or punch some bolts through so they don’t slide out when you try to roll it.
