48 degree w2’s on 59 degree block
The picture above is of a W2 for use on a 48 degree lifter block. The bolt holes are the same so they will bolt on to a 59 degree block. There are a few differences.
The valve angle is 15 degrees on these 48 degree W2 heads versus the stock, stock replacement and 59 degree W2 heads 18 degree valve angle. Therefore you may not be able to use off the shelf small block pistons that are for 18 degree heads. It will depend on the application, cam, ..... you may need custom pistons or pistons designed for W7-W9 heads which for the most part have 15 degree valve angles (except for some exceptions like the Lemans W8 head).
The location of the rocker arm bolt holes is moved on the 48 degree heads and the pedestal pads are machined differently and you can only use Jesel or T&D rocker arm set ups as cast. typical W2 rocker arm set ups do not bolt on and work properly.
I do not believe the geometry of the 59 degree block tappet angle, pushrod angle and the use of the 48 degree rocker arm set up on the 48 degree head will be ideal when installed on a 59 degree block. This should be discussed with a knowledgeable small block engine builder like Ryan at Shady Dell.
48 degree W2 heads are not drilled for shaft oiling. You need to use pushrod oiling as cast.