I had the bores bored/honed to 3.905 recently to fit the Diamond pistons that I bought. I am planning on spraying on it later probably around 250 or 300 so I know the clearances are suppose to be a little looser between the piston and outer wall. I installed the pistons last week and everything looks pretty good but to me some of the clearances "look" a little tight. I know it sounds crazy for me to say that it simply "looks" a little tight but I'm just trying to make sure everything is taken care of and checked and double checked before I start this thing up and beat on it. I don't want any mistakes. I was wonding if I could check the clearances with a feeler gauge to get an accurate measurement. Or should I just stop being so particular about everything and just put it back together? Here's some pictures of the bores. What do you guys think?

 

All the cylinders should be the same. You said , "some" . I'd check it. You can check it with a feeler gauge, but you'll need to take it back apart. Did you check the ring gap? I had my block honed and mine barely fit a .002 feeler gauge on the pistons. My speed pro rings gap checked at .020 in every cylinder. I was pretty happy everything was that tight. When engine building... measure 3 times, Torque once.

 

Using a feeler gauge is not the most accurate method, but you can do that in a pinch. Whether you use a feeler gauge or dial bore gauge, you must check it at the skirt. Pistons are barrel shaped, with the specified clearance measurements taken at the skirt.

 

Well to elaborate, I didn't really mean anything by saying "some". All the cylinders look the same just a little tight. The machine shop matched every piston to each cylinder and ended up opening them all up to 3.905". I'm probably just worrying too much about everything...