Visual difference in 302 vs 347?

Ahh, odd. I still may take the crank and get it polished up a bit more and check it when I take it for the balancing.

 

Yeah Ford started using .010 under size bearings in some engine back in the mid 60s, dunno when/if the practice was stopped... Could be rods, mains or both... Guessing they didn't want to scrap cranks with slight flaws...

The pistons in my 306 are stamped on the underside, no way to tell from the top side unless measured... No I dunno what brand they are, were already installed when I bought it...

 

I've seen pistons marked on the bottom like that too. But I've never seen .010 bearings on anything from the factory. I do know that you could buy those bearings right from the dealer though if you had to have your crank ground.

 

These were stamped below the rings. Dropped it off at the machine shop today.

 

That last one I pulled with .010 bearings was a 90's 5.0