Shaft extenders for 1950s MacGregors rocket shaft etc

Does anybody know what size shaft extenders I would need to extend numerous MacGregor irons I have.

I play with Haig Ultradyne II irons.

All my 1950s macgregors feel great but the shafts are so short. The long irons feel great but 5-PW feel so short and upright.

Any links would be greatly appreciated.

I’m 6’0 for reference.

Will these work?

I extended some 1950s rocket shafts a few years ago. I believe .580 was the correct size.

Remove the grips and measure to be sure. I’d hate to mislead you based on my memory.

I bet Mike would know off the top of his head.

I’ve never done this before. Aren’t the extensions severely tapered so that they will slide into any shaft regardless?

Thanks for the response.

No, you have to get the correct size. A .600 extension won’t fit into a .580 shaft, for example.

Outside of that, they’re very easy to work with.