Wanted to help out my daughter and show her how to tune up her car. It is a 74 with a 2 bbl/350. All stock. Just bought it so I don't know if there is a cam. A little old man's family sold it to me; but that doesn't mean diddly, I know.

I pulled the plugs (Auto lite 26) WTF?!? I thought all the 2nd gens ran RT44T Delco plugs? I looked it up and went down and bought the AC Delco R44T. Gapped them to .035. All plugs replaced. Cap and rotor looked fine. Checked belts... OK.

Set points to 31. Idle @600 read 8° BTDC. Vacuum adv capped and "T'd" during timing calibration. Idle sounded okay- perhaps a mite slow. I heard a retarded pop when she backed out to take a test drive. She said it was stumbling off-idle. Did the same in park when given a good hard throttle tap.

Seems like 8° is too low. Maybe 12°? Would a recurving of the distributor help?

 

What was your total timming? Initial timming should be around 12-15 BTDC at idle 30-32 total.

 

Was that a feeler gauge or dwell meter setting?

 

I doubt they went through the trouble of pulling the intake for a cam swap and not putting a 4 barrel on. Counter productive in my book. When you say you T'd the vac line during calibration, what does that mean?

Not all SBC had the same plugs. Things like combustion chamber shape and volume. Cam and carb too. Lots of variables really. I would have looked into what came stock although I'm a Delco R43 to 45TS usually. The number is just the heat range. I have Autolite's in my 383 outside, I think they're even 26's. The reason was based on looking at what others using my particular heads were using.

Do you have a dial back timing light? After getting one I don't know how I ever got along without it. I can't tell you anything about setting up points though. You motor is older than me.

Did it run good before you messed with the timing? Maybe it was a lean pop your hearing. Is the carb in good working order?

 

R44 plugs are what is spec'd, but the 43 is close enough. Dwell angle with a meter should be 28-32, so your 31 should be fine. Timing should be the 8 degrees, with the vacuum line pulled from the advance and plugged. Not sure what T'd is?
I'd play with advancing the idle a bit and keep track of where you move it, then drive test it. Also make sure it restarts and shuts off fine once it runs well.

 

Sorry about tossing around terms that may cause confusion. T'd (I meant: to plug the vacuum line with a golf Tee).

The points were set to dwell using a tach/dwell meter. It ran pretty good before, just wanted to tighten it up

********** I hate to admit it; part of the problem was I had mixed the 3-5 wires up***


Just for grins, I also went to 12° BTDC It runs ok, pulls good; but I guess I'll try 8° again, then maybe 10°.

Dial back timing light... no, never used one- seemed too complicated when I was starting out in the 70's- just been using a regular Craftsman.

I don't know what base and total timing are yet- no tape on the crank yet. Is there another way to check?

 

EdPDX I am with you on those dial back lights. I started working on hot rods in the late 60's. If you couldn't set your points you would not be going on your date. That is a very strong motivator and did a lot for me, as far as learning about cars and come to think about it, girls to.

 

Your base timing is what is read on the tab at idle. You woun't ever know your total timing unless you know how much mechanical your dizzy adds. This varied on GM HEI's I don't know about points.

With my dial back, I can set it to 34*. Then bring the engine to 3G, with the idle cranked that high or have someone hold it. Now if I rotate the dizzy until the mark is at 0* while at 3g. I know my total is 34*. Lock it down and recheck the base timing. TaDa!

Honestly I would put a stock HEI in there. They are the best stock dizzy ever built and are good to 4500-5500 in stock form. That or a Petronix conversion, I tthink those allow you to change the ignition curve with a little dial. I wish mine were that easy.

 

All my tune up equipment is over 40 yrs. old, so I'm still using a plain old timing light also. I install timing tapes on all my balancers, so it works fine for my uses. The tapes are only a few dollars at Summit, or Jegs.
I've occasionally swapped a plug wire when I got a little lax installing them. Happens to everyone once if they do much hotrodding.