Are LS stock rotating assemblies balanced? Reason I am asking is tha tI have a LQ4 and i bought new stock rods and pistons, so I was wondering if I would have problems???????

 

Anytime you switch components in a rotating assembly you should re-balance. They are well balanced from GM.

 

I have similar situation, new rods are 28grams heavier than stock ones and pistons weigh approx. same as originals, so bobweight becomes higher and that requires mallorymetal added to crank. At least here in Finland adding that mallorymetal or tungsten is quite expensive operation. That's why I'm thinking eventually of buying forged aftermarket crank, cheaper balancing compensates the overall higher price.

 

I weighed my stock rods and pistons and also my new rods and pistons. Here are the results:
Old New
1: 1208 1: 1208
2: 1207 2: 1205
3: 1211 3: 1208
4: 1216 4: 1203
5: 1212 5: 1203
6: 1214 6: 1205
7: 1212 7: 1203
8: 1211 8: 1204

Like I said these are the old Lq4 rods pistons and rings, VS: New Lq4 rods pistons and rings. Do you think these are within GM specs. As i understand, GM rotating assemblies are balanced but only to a +/- ? This is what I am trying to figure out!!!

 

jmo but I would get it rebalanced no matter what. I just wouldn't want to take a chance with something going wrong. Especialy with the bottom end.