My engine has to be bored, so should I do the necesary .30 over or go to .40? How much horsepower would each one add? Can my stock pistons be used after its bored? If they can, let me know where I can get a single piston from an L05 with 9C1 package. (Caprice police package) one cracked, and they were damn good pistons, i'd hate to have to buy all new ones

 

Ok, I dont know why my post ended up in Aftermarket Product Reviews, cuz I did not list it in that thread

 

i'd only go over to the next size, not anything extra. you won't make any more power, or not make any more power that you'd notice going over more than you need.

 

You can't do either, .30 or .40 over will cut your cylinder bore completely away. But .030 or .040 will work!!! If you can only go .010 or .020 if you can get pistons that size, save room for future rebuilds. You can't use stock pistons if you bore it, buy a matching set. You could find a good piston in a junkyard and just have the bores honed a little and reuse the stock pistons with new rings, but that is the poormans rebuild, it won't last very long, maybe 20-30,000 miles.

 

you can't replace a single piston. they're weight matched sets, unless you balance and match all 8 pistons.

 

I agree with everything said so far.

Only bore the engine as much as possible. If it will clean up with a .030" overbore then only do that. This way you save meat for future rebuilds. Small block pistons also often come in .020" oversize, so if you can get away with this it would be even better.

Replace all the pistons as a set. They are weight matched as noted. I've pulled engines apart that had one piston bigger than all the rest, and couldn't help but laugh. This is really the wrong way to go about a rebuild. You have the engine apart, and the car out of comission. Do what it takes to get another 150,000 or more miles out of it before it needs to be rebuilt again, rather than just cobbeling it together to get it running again. You'll be much happier with the results if done right.