I have a B30 6 bolt flywheel, I need a B30 8 bolt flywheel. It was suggested to me that I simply have the 6 bolt flywheel re-drilled to 8 bolts. Thoughts on the subject?

I too would shy away from the idea...

But, I did have a 164 to which the previous owner did exactly what you mentioned, and it was never a problem. You're talking some extremely precise machine work, and I'd still fear rigidity...

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-Matt I ♥ my ♂

I ran into the same problem as you when I did my tranny swap -- couldn't source an 8-bolt flywheel.

I took my 6-bolt flywheel to carolinaclutch.com and spoke with the owner there about what I could do. His company specializes in making custom high-performance flywheel/clutch combos (we're talking racing applications for 1000+ hp vettes and crap). He said that machining the correct bolt pattern into the flywheel would be just fine, and welding in the leftover holes would simply be overkill.

I mentioned that others had thought the flywheel would disintegrate and chop off my legs. He said that yes, it would . . . if I were pushing somewhere close to about 800 hp at roughly 8000 to 10000 rpm. In other words, no way, no how for a stock, or even highly modified, B30.

That said, my flywheel was in very good condition, so your mileage may vary. While the risk of catastrophic failure exists . . . I think the probability is extremely low.

On another note . . . weren't you parting out a 164? I'm in need of a known-to-be-good water pump. Got one available?
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74 164E

The usual suspects have new ones that are "known to be good".
I am pretty leery of used ones unless I myself put on all the use and know that they are pretty new.
Also prompt re-installation is a plus.
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George Downs, Bartlesville, Heart of the USA!

Who are the usual suspects? Everyone I called couldn't get their hands on one.
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74 164E

RPR in Albany, California, FCPGroton in Connecticut, IPD in Oregon.
I'm sure there are others.
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George Downs, Bartlesville, Heart of the USA!

I'm pretty sure I got the water pump for my 164 from Advance! I definitely ordered that and the alternator from the same place and they both work fine.

If the flywheel was steel, you'd just weld the old holes shut & drill new holes, but it's cast iron, so you can't weld it up cheaply + there is the risk that the flywheel could explode afterwards & remove one of your feet. (cast iron flywheels do that if you machine them wrong)

I'd rather swap the crank & modify the conrods to suit.

My thought is that it is a geometric impossibility.
You'd be better off having a custom steel flywheel machined from scratch.

I don't think you'll have enough meat left on the flywheel to do the job, but someone here will probably have the correct answer.