I hesitated posting this as I think I know my answer but here goes.

I sold my motor with bellhousing. I am working on another old CE block that I had. I have crank laid in this block and it has not been line bored. I had another lakewood housing that I attempted to dial in. I was amazed at the reading taken in 8 clockwise positions.
Beginning at 12 o clock, CW rotation,, I am reading 33, 14, 4, 1, 8, 35,45,45. I also find this opening at 4.689 and my Tko at 4.675. I am beginning to think this b/h opening is not true at all and I see no ecomonical fix for this unless I was going to a toploader trans. Would anyone agree with me that I need to put this housing out in the pasture ?. This is out of one of my old race cars and I do mean old. I dont think there are enuff offset dowels to correct this. Looks like I would need some .020 on one side and then be left to correct the 12 oclock reading.

So I venture off to locate a new Mcleod housing and I find two. # 8630 that includes a register ring and a 8653, which I dont know if this fits only GM trans or what, still waiting on Mcleod to open tech line. Does anyone have input here on this??

Don, it sure sounds like it's warped beyond working with. I'm sure you know CC5spd sell Bells guaranteed to be within .005". But they're around $240.

Assuming the hole in your bellhousing is perfectly round, you will be able to find two places directly opposite each other where the readings are the same (equidistant). In looking at your numbers your equidistant readings should be at about 1:15 and 7:15 on the clock face. Find both equidistant readings and mark their location on the bellhousing. Exactly 90˚ from the equidistant numbers you will find the lowest and highest readings. Your goal is to move the bellhousing toward the lowest reading just enough make the low and high readings as close as possible to the equidistant readings. In other words If you move the bellhousing .022 toward 4:15 on the clock face all of your readings around the bellhousing should be equal.

The four main readings you need to be concerned with are the two equidistant readings and the high and low readings exactly 90˚ from them.

I came up with the same thing as Steve. An .020" dowel set will get you to .004". If you can find .022's that will make her perfect.

How well does it fit on the TKO, is she tight enough?

Can you measure the face of the bell to make sure she's still square?
I'd probably poorboy this, set the flange on my good hardwood floor in the house, lay a 4' carpenters level on top, and measure from each end to the floor, rotate 90 and do it again.

Steve said it correctly at the beginning, IF the bell hole was true, but its not so we would have to split up another .012 ? As the bellhole is 4.692, Tko retainer is 4.675 on the button. So I got tired of jacking with it, Called GMJim and went to the 621 housing .
I feel safe with this as my flywheel is Hayes billet and CF clutch.
I did not mention about the face being parallel . Not going there. TKO too much to risk.
As I told Jim, If I recall correctly, I had a proshifted toploader in this bell so , it took a beating. Thats why the hole is about .015 larger. Done deal,, Housing will be here quick. Appreciate the comments.