Based on the runout calculation the original bellhousing alignment dowels pins had to come out. Even with the engine on a stand this can be a pain. So I researched different methods of removal, including heat, welding or impact. Not wanting to apply heat, and lacking the talent to weld a nut (or anything else for that matter) onto the dowel it basically left me with brute force.
Dowel pins are typically hard, at least case hardened. When I drove a center punch into the end to get the drill bit started, it made a nice indent. I had a sharp carbide-tipped 3/16" masonry bit on standby, but it was not required. After drilling a 1/8" pilot hole I was able to graduate up to a TiN coated 13/64" bit, then successfully tap 1/4-20 in. threads. Sprayed PB blaster through the new hole, inserted screw and started smacking it with my homemade slide hammer.
After about a dozen good hits (using two 5 lb plates) it popped right out! Note I had drilled at an upward angle so the 1/40-20 screw looks skewed but it held on for dear life, and unscrewed easily afterwards.
Here's the dowel pin on the table. Homemade slide hammer on the floor. The threaded adjuster in the vice grip handle was replaced with 12" of 7/16" all-thread. Even though not directly in line with the jaws it did the job. Total cost minus vice grips and weights - $12.
Access to the upper left dowel pin was obscured by the firewall. For the purists in the crowd I will spare them the picture of how we removed it, but it involved drilling a 1/4" hole just beside the gas pedal pivot and attacking from inside the vehicle. The hole is easy enough to patch - it was like minimally invasive surgery.
We tightened 2 nuts on the end of a 12" piece of 1/4-20 all-thread, which proved strong enough to yank out that dowel.
