Which stock balacer you use really depends on what accessory drive you want to run, assuming you want to run a stock accessory drive (F Body, Vette, truck) as they have different depths. If you are going to run truck accessories, run the truck balancer, unless of course if you want to run an underdrive balancer (smaller diameter than stock). There are lots of aftermarket brackets out there to repackage the truck accessories as well, so it just depends on what you want to do, but you don't necessarily need to replace the stock balancer.