If I use a 390gm piston and a 550gm rod (and a 118gm pin?) will this assembly balance to the stock crank without adding weight?
What is the weight of the stock components?

 

Yes and you will even have to drill some weight out as well since your new stuff is lighter. The stock piston is around 425-430 g and the pin is around 165 g, like a lot of Mahle stuff, it is pretty hoss. The rods are around 600g or so but I'm more fuzzy on those since we never use them? I know they're heavier than 550 g, that's for sure.

 

Funny you knew I was talking about Mahle stuff.

I am considering the eagle lightweight h-beam 6.125 rods, and the mahle pistons. Is there anything I need to worry about with the rods being the SBC off center rods?
Or should I just go with the stock length Eagle rod (for LS1)? The assembly should still balance right?

Thanks for your help here.

 

Well the stock GM pistons are Mahle too.

If the pin boss is narrow you may have to clearance the pistons depending on the small end pin width or it will touch on one side on a tight piston.