73 318 upgrade questions

Root beer, I've been down this road a few times with 318's. my question to you is, what kind of performance are you looking for. Do you have an idea of what gears you want to run?

I'll tell you what I wouldn't do though for a regular cruiser, Use a 2.02 valve!
Or a 340/360 head until I was looking at mid to low 12's. your stock head and the stock valves can power you into the 14's with 3.55's, and a small cam. No converter needed. Though it would help some.

My last 318 build used the stock pistons in a '78 - 318. It ran a 15.14 OOTB with 3.21 gears on stock tires, Jegs dual exhaust @'2-1/2 inch's hooked up to Hooker headers, an Edelbrock LD4B intake and a 600 CFM carb. The cam was a small Crane at 272/284-.454/.480 on a 112 C-line.

No shift kit, no extra stall converter, no performance distributor or up graded valves.

You can take a 1/2 second plus off the 1/4 time with a XE268 Comp cam (or similar) and a bit more compression. (A light head milling to raise the ratio) move to a set of 3.55 gears.
At this point, while a better stall converter would be a good thing to have, it is not a mandatory thing to have. But I'll bet you be glad when you do.
I seriously suggest headers at this point.

This upgraded set up still runs on 87 octane. You should be able to run a mid 14 easy. It'll be a strong runner.

Look into a Performer or Action plus intake, a comp or Lunati cam, and a MSD or equal like ignition.