2002 4x4 GMC ½ ton

LM7 5.3



Hello,

I am planning to have the block bored to get rid of the piston slap, it knocks until the temperature reaches 190 degrees. Also planning on putting in flat top pistons to increase the CR as it has the 7cc dished in it now. I am still driving it-------- so I cannot weigh the pistons yet.


My question is what is the weight of the stock piston and pin?
I have a book [ Chevy LS1/LS6 V-8s] that says the pistons is 434 grams, no mention of the pin. I have another book on order---so.

I have seen the stock pistons listed as 405, 414, 404-406, 434 grams,
pins 164 grams.


I must ship the crank out to get it balanced and I only rev to 6000 so I am trying to match the weight with the new flat tops and not re-balance.
Just trying to get an idea of what replacement pistons I should be looking at.

I will weigh the pistons when I tear the old rust bucket down and see what the block cleans up at before I order new pistons.

Thanks

 

factory engines are not usually balanced

 

if you have to ship it out, youre best shipping it with the rods and pistons you plan to run. Anything else is a best effort guess

 

OK, best would be to balance then. Port and shim the oil pump so I could up the RPM limit 6500-7000.
Thanks

 

OK thanks, looks like it is going to take this summer to do it right.