Check the listing for details. SBC OR BBC OR FORD RACE BALANCING UPGRADE. Condition: New. Listed at 125.00 USD. RACE BALANCING This service is an upgrade for those that have purchased a short block kit, rotating assembly or engine from our other listings. For those who want their engine to operate virtually vibration free at high rpm, the race balance is an exceptional option. Extends engine life and frees up a few more horse power. This is a somewhat labor intensive procedure and is not required, but the feel of an absolutely vibration free engine at high rpm is desirable by many. The standard balance job that is included with this assembly at no extra charge is certainly sufficient. With a race balance job, all pistons and rods are match weighed to within 2/10's of a gram or less, and the final balance is brought down to around 1 gram plus or minus. An ultra smooth engine at high rpm has a noticeable feel and sound to it. If you do not opt for this upgrade, the assembly will still be fully balanced. We spend a good hour and a half doing the regular balance work, and it will certainly meet your needs.