The problem w/ a come-along is it is over-powered for the task and thus takes a long time. A boat winch is more appropriate. I have various pulleys which let me rig a rope for more appropriate leverage. You can use physics to speed things. If you get a rope taught, then push on it sideways (F) you generate tremendous amplification to give tension T = F/[2*sin(angle)], almost infinite when the rope is straight. But, you need a rope that won't stretch (not nylon, use steel or poly). Have a helper release the brakes then apply to lock the position after each push. With no brakes, a helper could slide a brick behind the wheels to lock the position. Tighten the rope and repeat. You can inch forward fairly quickly if synch'ed. With 3 people, one can pull up slack and wrap against a tree to lock the rope each time. I am sure many off-roaders know such tricks when a winch is missing or isn't sufficient.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans