i have a b16a2. i just melted one of my pistons so i took the piston out and was going to put another rod and piston in that i had from a friends engine. the thing is on my rod it says pr3 39...on the new rod it says pr3 42... are they the same???? i know worse case i could change the rod. what do you guys think?

 

Just to play it safe, i would say to use the rod that was in the motor before because its probably balanced for that specific motor. While its off, you should get it stress tested, pop it in and your good to go.

 

thanks its back up and running i called honda and they said that the 39... and the 42... where just casting batches and that there where the same