Installing Harm/Bal and threads Stripped... WHAT NOW???

Just installed the 355 this morning and began putting the front of the motor together and when I was putting the power steering pump on the motor I found that it hit the 8" balancer, no problem, I had a 6.75" ready to install. I don`t know where this "THING" came from but it did not fit a SBC. I had a buddy come over with a caliper and found it to be .003 smaller than a typical balancer. I then decided to use the balancer from the 283 that came out of it and cleaned and painted and began installing when I got maybe half way and found there was a heli-coil (hope I spelled it right).
Removed the Balancer and tried to go with a larger size bolt and it started out good but again got half way and it started to feel like I was stipping threads. All I need is a stinking balancer on this motor and I`ll be alright, What do I need to do???

If I was you I would get a new one, I had a 283 that did the same thing. I had gotten to the last bolt and when I tightened it, it just diddnt feel right but I could get it fairly tight so figured it would be ok. About a month later that bolt came loose and took out every thing, belts radiator hoses and the pulley for my water pump. It sound like it has alread been fixed before so I personaly wouldnt take a chance with it. Check out ebay or check the junk yard just my 2 cent :D.

Two choices:

Install another heli-coil.

Install a stud and use a washer and nut to secure the damper. Cut off a piece of threaded rod of the correct diameter and thread pitch. Use 2 nuts jammed together on the outer end to use your wrench on to thread the stud in. Chances are if you chamfer the end that threads into the crank, you'll engage all the threads that are still good and you'll have a player.

Now, I've never had to resort to this, but I would think that if ALL the threads are stripped and you can't get the stud to get a good grip, you might mix up a batch of JB Weld and smear it on the threads and thread the stud in as best you can. Let the epoxy set up for 24 hours and the stud should be there forever. That does raise a question about what to do with it when you disassemble this motor to turn the crank journals, but hey, that's quite a ways down the road, huh?

Your problem in the first place is that you were using a bolt that was too short to engage all the threads.