Glad you guys found the problem. Knowing what went wrong makes it a lot more reassuring rebuilding it this time. I had a 289 in high school, that the parts shop sent a 302 crank for. When we rebuilt it in the shop, nobody caught the difference(myself, my shop teacher, and my friend who helped rebuild the engine)We all were frustrated at the noise it made running, but could never figure out what was going on. I must have taken it apart and reassembled three or four times. I finally talked to the local Ford dealership, who had me bring all the parts down. The measured the crank and figured out that was the mistake, but by then it was over a year later and the parts company had gone out of business. I was graduating from high school, and didn't have time or money to fix it! It still kills me 30 years later! I loved the 68 mustang until the engine failed repeatedly, I just gave up on it. Glad you guys found the problem and have the resources to fix it up!