The six-groove part of my crank pulley is missing.

You best call Ford Garage on this one, thats the strangest front crank pulley story I ever read. If that sort of failure exists ? They would know, and have a correction. Parts can tell you the new part number, service can tell you if there is an update, or engine bulletin. If it failed because of damage or road salt or something, you wouldd remove the old one for show and tell. whatever's left of it.

The outer part of the harmonic balancer separated from the inner part. You will need a new harmonic balancer. Ford part number F6ZZ-6312-AB. The Ford ones aren't cheap, but I would use a Ford part rather than an aftermarket in this situation.

Harmonic Balancer at Autozone is Dorman 594-081 for $59.99. To remove it will require a puller remove the remaining part and you probably want some experienced to do this repair. I personally don't like Dorman parts.

Also this is a somewhat common failure. Do a Google search for "Mustang Balancer Failure" and go to images and you will many of them.

I had a 302 in an 84 bird that was getting out of sorts. After pricing, used the balancer from a hi output, from the warranty scrap. they were the same, then,.... your number is 96, could be quite different.

If a 4.6L is internally balanced, you can just look for something that will support the pulley. No need to redesign the balance for "performance" at 380-810 dollars for aftermarket race car parts from what I read there, thanks Bob. there was a neat 8 rib for build- up planners, but jeez they really see these guys comin.

Dannyl, 4.6l Fords are internally balanced. You can spend $50.00 on up to $800 on a new balancer. I currently have a Steeda underdrive kit in my office that I never installed for a 2008 Mustang. Ordered different water pump pulley for it and now the kit will work on my 2004 Marauder 4.6l DOHC. Same balancer.

Then all you need for his car is what will hold together. probably had 3/36 powertrain unless he purchased more so 17 years is not too bad i suppose for a "balancer" and the ford part is still best all around. Use your 800 for maintenance and inspections that were missed. They really arent balancing, but supporting the front pulley. I have just removed one in my life. The romeo plant wanted replacement after the first few tickers in the early 90's. We did not have to tear them down after that. Problem? call the plant. "OK, sending you an engine", in those days.