I had a 60 L Grind in the bag for a while and found it to have the most heel relief (as described on the website). Unfortunately it also has more trailing edge and toe relief, which requires a more delicate touch when squared up and in softer conditions. When opened up for shorter ones, it was a great club but ultimately the trade off on the square faced shots (and the fact that I almost always play in softer conditions) led me back to the M Grind I played previously. If you’re looking for just heel relief it might be worth looking into the higher bounce/full sole options (S Grind and K Grind) and having a local club fitter brush off a bit of the heel. Justin Thomas does this with his 60 degree K Grind; I believe there is a video out there of it being done. Of course, all of the above needs to be taken with a grain of salt. Trial and error work best for me!