No, tossing the keys on the counter and going "Do the HEI upgrade" is not going to happen. That's why there's a detailed article I linked you to, going step-by-step on how it's done, what parts you need, etc.
Pretty much nothing on your '73 Valiant is common knowledge any more. Most of the knowledge that used to be common about these cars can no longer be found (in heads or in books) at most shops, which are equipped and staffed and trained for the last 25 years' cars.
