hei on 300
http://www.ebay.com/itm/875-DISTRIBUTOR-FORD-300-F-150-F-250-PICKUP-HEI-CAP-UPGRADE-COIL-MODULE-INCLUDED/141606721036?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20131017132637%26meid%3D239ce484cb0f4c7a8f9e7989dbf9f8bf%26pid%3D100033%26rk%3D1%26rkt%3D4%26mehot%3Dpp%26sd%3D141606721036 currently $94.99 with $25 shipping.
on FordSix there have been several threads about the aftermarket HEI type distributors, I didn't find one for the 240/300 but I did find one for the small sixes.
got my gm style electronic dizzy today -- FordSix Forum
This is where I found the original eBay link
300 inline 6 HEI mod? -- FordSix Forum
FWIW, I am running the cheapest chinese made Small block (289/302) HEI type distributor I can find off Amazon, it was only $48 when I bought it 2 years ago, so far we've put over 15,000 miles on that car/motor and the only issue we've had is that the coil dot/pin (whatever that nipple thing is called between the coil and rotor -- maybe center electrode) went to hell and was ground flat by the rotor, easy fix by purchasing a new cap/rotor. I didn't have it recurved nor did I change out the drive gear.



