Replacing BB Spindle HELP!

I'm trying to replace a spindle on a GT Timberline with a cartridge BB. I have measured the OA length of the spindle at 68 x 125.2mm. On the spindle is inscribed:

VP 3S
05.01A

I have been told I need a cartridge that is 68 x 127?

Maybe i need some hand holding but is that correct at 68 x 127?

I'd appreciate any help.

In the grand scheme of things, the difference between 127 & 125.2 is infinitesimal -- if you the BB your shop is trying to sell you has a spindle which is 127mm long, then that's probably the one you should buy BECAUSE unless you used calipers to do the measurement, you are probably off by a small amount in your measurement.

The ONLY (?) caveat is if your frame has a 73mm BB shell ... then you need a 73x127 (presuming one is available!?!).

Take your vernier caliper to the LBS and confirrm the measurements of the replacement part to your satisfaction.

Their vernier caliper/micrometer may be different to yours. If it is only a matter of a few 0.1mm or two then it's your choice as whether to accept the variation or not.

If you leave it entirely in their hands then they must get it right.