My original 1983 Warmoth Strat. that was assembled by a Luthier that I've since lovingly called "The Butcher of Swissvale"
messed up the neck pocket somehow and it's been 'not very tight' ever since the first day I got it.
But, the 4 neck screws that hold the neck in place take care of the problem very well.
All I need to do if I take the neck off ........ and then put it back on is:
1) Put the neck back on but don't tighten the screws down very much - so there is back and forth play.
2) Put the Low E and High E strings on with only enough tension to see a straight line in them.
3) Visually align the High E and Low E strings by moving the neck this way or that way while maybe tightening up just a little.
I don't want vertical play (front to back) ... just loose enough for it to be able to move left to right.
4) When the alignment of the strings looks good I tighten the neck screws all the way and string it up.
For the alignment I mainly watch the distance of the high E string from the edge of the frets, from the nut to highest fret,
going for as close to the same, all the way from the nut to the top. The Low E then just falls into place correctly.
It works great all the time.
The neck has been off this body plenty of times since 1983 and always gets put on in what seems to be the correct place.
Out of the 4 Warmoths that I own it's always been my go-to, every day guitar, always right here beside me, ready to play.
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If your gap is big enough, then maybe you can make a 'drop in the side' shim out of some really hard wood.
Maple would probably be fine ... but there are harder woods.
You'll probably have to hand craft it to the correct size and angle, but once you get it right then it should be good forever.
I'd just not glue it in until you're absolutely positive it's correct. Maybe never glue it in.
Let us know how it goes.
Good luck!
