Need help with 306 build specs...

For a 306, your basic 302 with an .030 in overbore, all the stock specs apply. The only difference will be the actual piston and bore dimension. The clearance dimension should be the same.

I would get a Ford, Chiltons or similar manual. The crank clearances are also the same as stock. Be careful and check the dimensions in a couple places, as my oem 79 shop manual has some odd, but critical misprints.

If you are using the crank again at standard dimensions, you should not have much problem. I checked every main and rod bearing with plastigage.

You can hone with motor oil, kerosene, diesel, or WD40.

Lighter seems to be better since it spreads and collects chips better and gets into the hone stones. Just wash the heck out of it afterwards with soap and water.