My 289 has 2 pistons that have been scored. First, no there is no other damage to the block. They had ridges and I sanded them down but now have piston slap. I planned on replacing the 2 that are damaged. Then I got a deal on 4, although not a whole set, I thought I could change the two adjacent, like 4 and 8, and 2 and 6, as they are opposite each other on the crank. So, could I replace the 2 damaged alone and be ok, or should I go with the adjacent thing and use the 4 I got. Or, finally, and yes I know it is best, but should I do them all. There is no other damage again and the rest of them actually still have some knurling on them so I know they are good. I'm thinking more a balance thing. What to do???? Thanks!

 

Rotating assembly should definitely be balanced. If I was going through the trouble I would swap all and new rings, bearings etc.

 

i agree with " coda618 " i would go ahead and run the extra mile. if you only replace a cuuple, you will have 4 new ones and 4 old ones, when it comes time to replace the old ones, the new ones now will become the old ones and possibly reduce your horse power. that may not make sence, but bottum line i would replace all the pistons, rings and bearings while you are taking the time to do it now... just my 2 cents worth..

 

I have new rings, bearing, etc, but since I needed 2, had four, I wondered. I hate when I'm right. Just gonna get a whole set and off the extra ones I now have. Thanks for the input!