Balancing Rotating Assembly

Is balancing neccesary when rebuilding an engine? I plan on building the low end basicly stock, except for a little hotter than stock cam. The top end will get high performance heads, mabey AFR 165 or Edelebrock performer and a good intake.1990 Mustang, 130,000 miles.

Always a good idea but not necessary. If you change pistons I would recommend it. Fords seem to be more forgiving on the issue.
[addsig]

why wouldnt you balance? its one of those little things that will put you on top of the guy who didnt get that little extra thing done.

Unless you change something like the pistons that would have an affect on balance it is not nessesary. I reused the stock pistons when I rebuilt the bottom end at 140K miles, and just replaced rings and all bearings. In order to balance the rotating assy the pistons wouuld have had to be pressed off the rods. The cost of ballancing is added to the cost to disassemble and reassemble the pistons to the rods......$300-$400. I have had no issues with balance.