A typical older L6 (4 mains, long stroke) only needs a damper in a few places in its working life.
These "orders" are determined by crankshaft stiffness (which can be calculated, but the math is very bad), generally between 200 and 300 cycles per second, and RPM.
Rating common crankshafts by design for stiffness, highest first:
V6
V8
L4
L6
L8
For a 235, only 2 orders (the 3rd and 6th) fall within the normal RPM range. The 9th (and higher) order is too slow for practical use, and the lower orders are above any RPM you would use.
If the engine never sees continuous service very close to these 2 orders it doesn't need a damper. Chrysler tried this (and got it wrong) on the 241 hemi motor: no damper at all, but the motor was used in this range and the cranks broke.
If it does need a damper (viz., 1 of the orders occurs at a common cruising RPM) only the correct damper (tuned to this point) will help.
A billet, carbon-fiber, titanium V8 damper has no effect at these points, it's just money hanging there. It "protects" against harmonics in V8 orders that have no effect in an L6.
Please note: the SEMA damper standard (S.F.I. 18-1) does not rate a damper's effectiveness, or certify that it works at all (let alone on a specific motor) - only that it didn't explode during the test.
