You can run .060 gap just like originally recommended on a stock Delco unit....just not for very long. Then GM got smarter and reduced the gap, eliminated a lot of HEI problems.
Aftermarket stuff is ok for the most part. But if you're running stock HEI, there's no reason to spend the extra $$ on aftermarket parts unless you just want to. The stock HEI is more than up to the task for a stock GM engine if you close the plug gap to no more than .045. Just get good brand name parts. If you need a module, search on ebay or somewhere and get the OLD Delco parts and you can rest assured it'll work fine, and there's a good chance you may get it for a good price. Maybe not, as some of these cheese wipes selling them automatically think older Delco parts are antiques and try to value them accordingly. Shop around. But normally you should be able to find a Delco part for about 1/2 the price of the Accel part. Always use the heat sink type dielectric grease (this is important) under a new module where it contacts the distributor base. If it comes with a little grease packet...USE IT.
Of course, if they're relatively the same price, flip a coin. Accel isn't a bad thing, but it's not necessarily better on a stock engine.
You should have a 4 prong ignition module, original p/n 1875990, superseded to 10482820, and finally 19180771.
But there's a possibility of a 7 pin module, which would be 1977907, 1978617, 1978744, 16140189, 10482836, 10482832, and finally 19179581.
