Sheave/rope priority

[JohnV]

Hello--
I have to replace the worn-out rope halyards in my recently-acquired Alajuela 33.
There are 3 pairs of bronze-bushed aluminum sheaves in the masthead, and they are grooved for wire/rope halyards. I'd rather use all-rope.
My choices seem to be to either replace the sheaves, or to switch to rope/wire halyards.
Acetal sheaves of the correct dimension (about 3 1/8" in the slot) on the market all seem to be too wide (I need 5/8"). New aluminum ones are out of the question due to cost.
So-
Is it ever viable to have the old aluminum slots turned down to a rope groove? Can a local machine shop do it or does it require a specialist? If so, know of any good ones?
Or is going to wire/rope, with its various potential disadvantages, going to be my most realistic option, economically?
Thanks for any ideas.
John V.

[Brion Toss]

Hi,
Sorry to have been so long in answering. Turning down the sheaves is indeed an option, so long as the result doesn't reduce the diameter to the point that the halyard chafes on the mast or anything internal. No sharp edges, either.
Fair leads,
Brion Toss

[JohnV]

Thank you for the reply. If I get the new rope grooves turned down to about the depth of the wire grooves, I shouldn't have a problem. I'll note the sharp-edges concern. It seems like a pretty straightforward job for a machine shop.
John V.