As in previous thread I was looking at options for a new crankset to swap to for a 36t option for a loaded bike.
I saw this raceface crank for next to nothing
https://www.wiggle.co.uk/race-face-ride-narrowwide-single-ring-chainset?sku=5360612639
My bottom bracket is ultegra hollow tech two. And the frame is 68mm.
First off have I bought the wrong crank?
Adding it’s the right one then I guess I need some spacers?
Anyone able to point me to the right ones and how many do I need?
Thanks.

The ultegra BB cups are slightly narrower than the MTB equivalent so you’ll ideally need a MTB bottom bracket. (or fill the gap with axle spacers)

Any hollow tech II MTB bottom bracket will work and you put 2 spacers on the driveside, 1 on the non driveside for 68mm.

Only caveat here is your frame may be made for road cranksets if a ultegra BB was fitted so your chainline may be way out with a MTB crankset / BB.

Mmmmm. Ok. Can the chainline be corrected by putting the spacers on the non drive side?
It’s a grx 1x setup if that makes a difference.