225 Slant, Holley 1920 base tune?

Howdy! to make a long story short, i've been trying to get my 72 Duster roadworthy as well as teach myself how to do everything as I go, and I got it to crank, and idle(ish) but it was rough, noticed the coil was arcing, swapped it back to a factory one and it smoothed out some more but it was still way off and idling high, and if i lowered the idle, it would kind of just lean out and die So I tried richening the mixture a bit and now it doesn't idle on its own and I can't start the car and jump over to the front to keep it alive by hand by myself. SO.

Is there a way to practically "bench set" my carb on the car?

I basically need it to be generally in the ball park so I can go through and set the timing and let it get warm to set valve lash etc. Just waiting to get it into that elusive "smooth as a sewing machine" slant territory.

Also any general tips are appreciated since its basically me, myself, and I with the internet figuring this stuff out or if you're in North GA, just come wrench with me.

@RustyRatRod Help a brother out! Screw idle in to seat and then out 1.5 turns. Start with that. loosen idle screw and turn it in just to crack it. Does your 1920 still have a working choke? It should light off in under a revolution with some fuel in the bowl. Before you do all that, check your valve lash, I .011/ E .021 cold should get you running. Also check your exhaust heat riser valve, see if it actually still moves....if its really stiff, make it stiff in the open position, ie rotated off the stop. THat wont stop your car running but it will make it run better when warmed up. Those 1920's can get gummed up in the valve body in the fuel bowl. Have you tried to clean it yet? Once they are set up, they really do run like a sewing machine.

The 1920 on my '68 was a reman before I got the car. Even if you don't buy a kit, go through it thoroughly. Float was completely off. Before I adjusted that, I was afraid to even pull out into traffic it was so slow. Didnt remember slants being that slow. Night and day difference after adjusting.

I'll second the heat riser too. Mine ran hot, etc. Just looked at it again last week as it froze up again, just not completely closed. Keep and eye on, as I will too from now on.

so just to clarify, "Screw idle in to seat and then out 1.5 turns" is for the mixture and the other one is for the actual idle screw?
I believe the choke does work since it cold starts easily and it opens a bit although I really haven't gotten it to run long enough to see if it opens all the way.

I'll see about the valve lash today.

I'll also check the heat riser valve. I know the part that sends air back into the air cleaner works well enough to blow in my face when I was trying to get to the idle speed screw

I'll also look at the carb. this isn't the original carb on here, its a reman that got put on the car a few years back and it "ran" but it was always questionable. I do have the original and a rebuild kit so if all else fails I can try my hand at rebuilding a carb.

Ultimately the slant isn't the long term for this car but for now I just want to learn as much as possible and at least have a cruise-able car while I save for parts and start working on the body and interior. also being an old jeep guy, I'm a complete sucker for a good i6.

Update: got in the garage today, and adjusted the carb per @pishta 's recommendations, and set the valve lash cold which i'm glad I did because they were all over the place on clearances. The car started real quick from dead cold. I also checked over the heat riser valve and its not even stiff at all so that's good. I even got it to go in gear and move around the driveway which is a BIG win. I did learn, however, that I forgot to tighten the pan bolts all the way down when I checked over the timing chain so I get to clean that up. Overall I am super stoked with the progress. The only new development is the exhaust manifold seems to not be seated around cylinder #5 so I'll check all the torque on those next time I'm out there. Only a few more odds and ends (and less important things like registration and insurance lol) before some road tests. Thanks for the help y'all! I'll be sure to ask some more dumb questions later so until next time!

Nice work! The torque specs on those manifolds (either as they share the same studs) is like 10-12 ft lbs, hardly enough to keep them from vibrating off! Center 3 verticals around the carb are 22 ft/lb. If you can't get #5 to seal with 12 ft/lbs, you may have to get it fixed with a new one or 'pad' that one with stacked piece of gasket under its runner.

Quick update: Got the manifold torqued down, the bolts on the bottom were barely hanging on there so those were the culprit. I also got the pan bolts tightened down so now its a rather slow leak (and for now, I'll take it as a win and just stay on top of the oil level before I scoot around since I have no interest in fixing the pan gasket. It's running pretty good and not too shabby considering its 48 years old and me just figuring this stuff out. I also managed to take it for a short test drive and it went great. So I'd call it a win. I'm sure I can and will keep fine tuning it to get it better but for now I'll turn my attention to some other details around the car. Thank you so much for your help and I'll see you on the next one!