Aligning your tappet blocks is ESSENTIAL when assembling your engine.  If the tappet blocks aren't properly aligned, the tappet roller won't be riding square on the cam lobe and premature lifter failure will be the result. 
 
These tappet block alignment tools are the best on the market.  Their dark gray color is indicative of their special nitro-carburizing heat treatment.  This provides corrosion resistance, lubricity, and a level of hardness that will ensure they never wear out.  These are sold in a 3-pack, so you can align 3 holes of a lifter block, put in the first screw, and replace each alignment screw with the other mounting screws one by one until the lifter block is fully installed.  
 
We have two versions available:
1) The 1/4-20 version (Fast Eddy Co. No. 32) works on the lifter blocks of all big twins from 1977-1999  (late 1977 is when H-D started tapping the holes with 1/4-20 thread).  They can also be used to align oil pumps on twin cam models. 
2) The 1/4-24 version (Fast Eddy Co. No. 33) works on the lifter blocks of all big twins from 1936-1977.  These are especially important when using late shovel style lifter blocks, which don' thave self-aligning (countersunk) mounting screws, on earlier engines.