Need Help With Wiring.

No. You have enough to learn as it is and the digitals don't have a great rep.
Choices:
Use a points distributor set up for '67 273 w/ 4bbl Advantage - no wiring changes.
Disadvantage if you drive a lot points need some maintanence and replacement when worn.
Disadvantage is cost/availability if you want a dual point.

Use the points distributor for a 273 HiPo with an MSD 6 or similar.
Advantage - good advance curve for the engine, Little wear on the points.
Disadvantage - cost of MSD
Disadvantage - some wiring required but advantage is original harness stays intact.

Use a Chrysler electronic distributor with an advance like the ones in the original Mopar performance ones,
Plus MSD 6A.
Advantage - no points to maintain. Original harness stays intact.
Disadvantage - some wiring required.

The last is the one I'd think about if you want electronic. Rick Eherenberg (sp?) sells a distributor supposed to be the same as the old Mopar Performance ones. FABO member Halifaxhops sometimes has them too (not new but just as good).
If the car already had a Chrysler ECU on it, then I'd say just use that. But since it doesn't, the MSD 6 analogs is easier to wire up and still seems to be pretty reliable.
HEI based setups are not as plug and play. Stick with something easy. All the ignition system needs to do is light off the fuel at the right time. When it is burning good more voltage or longer duration isn't doing anything. The most important thing is ignition timing.

If the '74 360 still has its distributor, its going to have a 'smog' curve in it, even if it was a 4 bbl. You can use it if the initial advance is reduced by welding. I'm going to assume that's deeper than you want to get. But you can send it to Halifaxhops (he'll do the same thing without welding). Don't fall for the limiter plate chit chat. It can work but it can also not work depending on the situation. If it doesnt you'll be in for a ton of trial and error work.

my .02 and then some.