Typical variance on 6040 bed height?

My new 6040 bed has a run of 1.4mm height across the x axis (x0,y0,z0 to x388,y0,z1.4).

This seems quite a lot of slope- how typical is that much difference?

In mean time I have compensated by milling spoil board flat.
I'm thinking of adding a shim on the gantry leg, but I need to check tram of spindle 1st. I hope its out by same as gantry/bed cos then shim will make everything better.

Spoil board milling will be fine, but I also want to mill some metals using a vice etc (no spoil board).

It isn't big enough to be that far out, measure it and fix it, or mount your vice on a spoil board.

Yeah, I'll measure it up again with more data points. I'm waiting on a dial gauge arriving to check the tram on my spindle. Hopefully a shim under the left leg of the gantry will be viable. If the tram is currently bang on, I might even consider removing some metal from the bed. I'll remeasure first.

Thanks.