Richard & Bob, I respect both of your experience with engines in general, and specifically Healeys, but the damper delaminating is a real thing, with serious potential for collateral damage. Marvin on here, IIRC, has the remains of an engine from Layne Perkins, that snapped off the crank's snout at the #1 main bearing; Layne was just
idling through his neighborhood at maybe 20-25 mph when his BJ8-PII's damper came apart, after having visited me in the hospital (1987 gall bladder removal__the old fashioned way). Granted, before turning off the main road, Layne was probably running close to the red line__as he was often prone to doing...!
I was moving around the loose engine for my car on a dolly in my shop, and just barely bumped some object on the floor, easily knocking my earlier 100/6-3000 style (2-piece) damper apart. Though it ticked me off at the time, it was really a blessing, and upon closer examination, it was apparent that the bond had been losing its grip for some time, that being the final straw. This too was in the late 1980s (moved from that location in 1989). In the then most recent previous rebuild, the entire rotating/reciprocating assemblies had been dynamically balanced, so it should've been as smooth of a running Healey as you can get
In all my years of working on Healeys, I have never seen one delaminate. The dangerous harmonics that come into play with our 6 cylinder Austin engines are when you get to 5900 RPM. So, if you are racing then you want a better harmonic damper. If this is only a street motor, then no worries.
I've not heard of a Healey damper delaminating, but I once had a 4-cyl Cherokee damper do so. It made a mess of the radiator, so I had my BJ8's damper rebuilt at about 180K miles by Damper Docs (no complaints).
Pro Race damper on sale for $275 plus shipping at British Parts Northwest.
That's a killer price; I think I paid nearly double that__at least $400.00__when I I bought mine! Makes me want to buy one or two now for the (spare) Healey engines that I
might never even get around to rebuilding (my original 100/6 & another 3000 engine)!
Duane, my recommendation would be to take advantage of the above mentioned sale, and go with the Pro Race damper. Though a deviation from 100% pure stock/original, if painted green with the rest of the engine, only a few would take notice. Worth the deduction for the peace of mind if you actually intend to use the car.