Ok I found my answer by going through the IPLs. ( I always forget to do that!)
So this isn't mentioned much anywhere that I could find so it may be interesting to husky 200 series guys. Most of what I found say the 266 intake blocks are the same as the 66,162, and 630. This is true if the 266 block is 1987 or prior. It's not true if 1988 and later!
In 1988 on the 266, husky moved from a short m5 bolt to a short m4 sleeved carb bolt just like you see on the 268 and 272. The difference between these two sleeved m4 bolts (late 266 VS 268/272) is the length of the bolt. They are always shorter on the 266 since the intake block has it's own mounting bolts to the cylinder vs on the 268/272.
Part numbers
1988 and later 266 uses block 503492401 with the m4 carb bolt - 503496902
1987 and earlier 266 uses block 501511803 with the m5 carb bolt - 501777901
You can use any 266 block on any 66,162,630 or 266 regardless of the years, so long as you have the right carb bolts to match the block .