Have run into this before, but previously I have just used original Y block clutch bolts after searching high and low but never finding any new or ARP versions. Don't have any original bolts left (or I have 2 bolts, not enough...). This is an FE 184 tooth flywheel of unknown year only tapped for an 11" long style pressure plate. There are also 12 untapped 0.333 diameter holes around the perimeter. I presume those are holes which could be tapped for some unknown year diaphragm style pressure plate, but that is another issue and I have the long style pressure plate already. Anybody knows what year FE diaphragm clutches would fit if those holes were tapped, please chime in... The pressure plate bolts for the long style pressure plate are not 5/16th bolts, they are slightly smaller with a shaped unthreaded shoulder near the bolt head which matches the 6 countersunk drilled and tapped holes in the flywheel to center the clutch plate. So,these 6 bolts were both the fastener and the locating pins in one unit. Typically I found them on original ***emblies with a small lock washer on them also (the days before lok***e...). Tons of listings for the 5/16" or 3/8" new or ARP, but that is not what the bolt diameter is with the long style pressure plate. They are just a 1/2" head and my caliper shows them to be 1.043" overall length, 0.820" overall shaft length, 0.50" thread length with the remaining shaft length comprised of the shoulder of about 0.32" in length and 0.310" in diameter. Outside diameter of threaded section appears to be 0.302" Pretty sure when I used the saved bolts before that they all came from 54-62 Fords. Probably were all off of Y block pressure plates. Is this the same size and type of shoulder bolt that was used on flathead motor pressure plates that look to be the same design?
The bolts for a standard Long style pressure plate are a standard 5/16"-18 thread, the actual thread o.d. measurement on a standard 5/16" bolt is .305-.308 the shoulder on the pressure plate bolt is .312 which is just enough to locate the pressure plate on the flywheel. When I redrill for a different size pressure plate I drill and tap for 5/16"-18 thread and then counter bore the holes with a sharp 5/16" (.312) end mill x.200 deep, that duplicates the factory Ford thread/counter bores, or for any others that use a Long style pressure plate.
Looks like the multiple packages of aftermarket bolts I have and which I thought were ordered for a 390 a few years back are all 3/8" size, so larger but still with the locating shoulder. Must be for a 5.0 or something.. Well then, I will send for some ARP 5/16" and see what happens. Thanks for the feedback.
While you're in the middle of all this you may want to think about changing the early ring gear to the post 65 gear so you can use a 65 up starter and get away from the first issue unit that is getting very hard if not impossible to come up with over the counter these days.
I actually have a whole bunch of those early starters, but this flywheel and clutch is actually going on a 460 with big spline toploader and a 1987-1996(?) 460 external slave hydraulic actuated clutch and bellhousing. Same mounting as a T19 apparently. So I doubt those starters bolt up to the bell and will require a short throw later or aftermarket starter. Have to mock it up, but waiting for some pushrods before taking the engine off the stand. I thought the 184 tooth flywheel was the 65 up ring gear and the pre-64 was 176 or something like that? I looked up every ARP pressure plate bolt listing for vehicle equipped with a 352, 390 or 428 and the part selection message consistently came back with the message "this part does not fit your vehicle". When I went to Pioneer PP bolts it did come back as fitting all the earlier Ford V8's... But apparently the part is the same and fits despite the erroneous "does not fit" messages...
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