It is not difficult but a bit tricky; there is a turnbuckle on the side of the ZF.
"only" to adjust so the gear stick is in the middle of the gate and tighten the nuts without

the gear stick is moved.
a very small movement on the turnbuckle is quite a change at the gear stick.
it is difficult to find good (non overbore) 351 cleveland around where you live?
expensive?
Anders