So I think I'm going to hack Swords & Wizardry whitebox to suit my own needs. 95% of it is perfect. However here's the house rules.
Rolling a 20 on a hit does double damage for both PC's and Monsters.
Instead of a cleric turning table, it will be the same as the saving throw matrix. When a cleric attempts to turn they have to roll over the number (dependent on level) They also roll 1d6, if a 1 comes up the undead is completely destroyed rather than turned.
Same goes for thieving skills, it will be using a saving throw type table to cover all those skills. I know this will make the game a bit more swingy, but it will also be rules lite. To which I'm going to add a thief class to the game.
I'll also trim down the gear table and create a few adventure packs as well for quick character creation.
Ability checks will be based on DC's that become easier as you level up.
That would be about it.