'68 318 to carbed Magnum 5.2: Check my checklist
I thought about suggesting you buy a set of EQs, but I'm under the impression you're trying to save pennies where you can. Keep in mind, many magnums (as you've found already from searing on google) suffer from head cracks...I'm pretty sure the heads on my 5.2 are, since the donor '98 Dakota had over 200K miles on it