Soliciting opinions:
In my naivety, and pursuit of weight saving/heightened acceleration, I installed one on my spare motor (soon to likely be called to duty), not realizing how that might affect roadability, considering the E-4 Isky cam also. Reusing the iron OEM one (should it be resurfaced/balanced?), could complicate matters. I anticipate less driving my ‘55 as I progress into my 80s, so should I just live with it? Anyone out there with actual experience to share?

6 VOLTS/POS. GRD. NW INDIANA

The rule of thumb is for the flywheel weight to be 1% of the vehicle weight.  For a 3000 lb. car that would be a 30 lb. flywheel.  Having a flywheel that’s too light makes it difficult to leave smoothly from a stop without bringing up the engine rpm higher than normal and then riding the clutch longer.  For an application like a circle tracker where the clutch is not used except at the start of a race, the lighter flywheel does allow the engine to accelerate quicker out of the turns while also allowing the engine to decelerate faster (less braking) going into the turns.

Just my experience so other opinions always welcome.

Lorena, Texas (South of Waco)

Considering my OD trans. & rural location, I’m tempted to keep it. I also obtained a concentric clutch assembly, but wasn’t sure I would install it. I wonder how it would then effect operation (?).

6 VOLTS/POS. GRD. NW INDIANA

Years ago, when I was accumulating parts, I made the unwarranted/bone-head assumption that the stock clutch fork/throw-out assembly would successfully operate a concentric clutch.  I’m now having doubts, as it appears an aftermarket hydraulic rig may be required (?).  I may thus just change the discs in the OEM unit (already have  them).

6 VOLTS/POS. GRD. NW INDIANA

" ... stock clutch fork/throw-out assembly would successfully operate a concentric clutch.  I’m now having doubts, as it appears an aftermarket hydraulic rig may be required (?).  I may thus just change the discs in the OEM unit (already have  them)."

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Daniel what do you mean by concentric clutch. looking it up im getting hydraulic release bearing or dual disc clutch. are you referring to the pressure plate with diaphragm springs? for diaphragm pressure plate mechanical linkage is fine as long as you have flat faced bearing that contacts correctly and have proper air gap. If go hydraulic make sure you have enough travel to release fully and a pedal stop to prevent overtravel. 
Seth

I likely won’t bother with it, and it will end up on eBay eventually.  I also have two spare bell housings, in order to choose the most accurate and thus achieve the least trans. wear  (though whoever inherits the car will be the only one who benefits 😁). Admittedly, I have zero experience with clutches, but assume a drop-in inexpensive/rebuilt OEM pressure plate would be simplest, and probably warranted with the alum. flywheel (100K+ miles on my current clutch). I already have a new throw-out bearing, and the discs are the right diameter/splines.
 I should have remembered that when dealing with aftermarket upgrades, there are always unforeseen complications.
 There must be a reason the concentric diaphragm units apparently all seem to need hydraulic operation (?)

6 VOLTS/POS. GRD. NW INDIANA

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6 VOLTS/POS. GRD. NW INDIANA

I had talked with ram because i needed an 18 spline clutch disc for a 10" car bolt pattern.  they have a long pressure plate that can use their 10.5" clutch. the aluminum flywheel may have different options for different pressure plates as well. if you've got a diaphragm pressure plate that fits your flywheel id run that with stock clutch linkages and release bearings. for some reason i cant follow it but KISS is the best way, especially if your not planning to own it for long and helps resale.
Seth