[hurryinhoosier62]

Adamo, any reputable crank grinder should be able to weld the thrust flanges and regrind them to the proper width. The most critical part is welding the flanges. We had a submerged arc welder that was built for this purpose. The trick is interlocking the individual beads without leaving a void or overheating the base metal. Any crank shop with the required equipment could do this, but most shy away from welding nodular iron. On a forged crank it is actually easier. This is how Smokey built his first 3” main 421 in 1961 when the factory sponsored Pontiac teams were burning the bearings out of their 421s. He took a 421 990 crank, welded the thrust flange, cut the mains and thrust flange to 389 specs and installed the modified crank into one of his 389 Super Duty blocks.

[Mean Green]

What exactly is different with the thrust between 3.25 and 3.00 cranks?

I have a 4.50 stroke 3.25 main crank with center counterweights that I'm going to have cut down to 3.00.

The IA block that it came out of has small welds to hold the thrust bearing tight to the block.