'74 R90S crankshaft in R60/5 engine case ?

[KenHawk]

900cc. Would the R60 cam work good on a 900 kit?

From all reports an R60 cam is not a very good choice for use with the larger engines. Use a 308 as specified by the factory.

[vanzen]

I will say that re-ground crank failure will often be the result
of failure to properly heat-treat the re-ground journals.
(heat-treating does not penetrate the surface very deep, regrinding removes that treated material)
Proper radiusing of the corners of the journals is also an often overlooked feature of a re-ground shaft.

Best to find a good used crank in any event – and they are pretty damn sturdy items !

[gspd]

+1
But somebody on the planet must be reginding 247 cranks properly.
BMW has been listing oversize bearings forever and they could have no other use.

[ME 109]

Is regrinding worth the risk when a good s/h crank can be found for perhaps the same $ as a re-grind?
I would go for peace of mind, and not wonder if the crank was going to break every time I hit red line.
Not that red line is any particular 'breaking point'

[gspd]

I don't have that problem,
my new VDO tach has no redline.
I've always ignored it anyway, but t's less scary this way.