MSD 6AL-2 PROGRAMMABLE Ignition Control in a Squarebody, say what?

[Gregski]

If you are like me and like precision, control, and spending money on shinny new parts only to strap them on to your old rusty rig then you might enjoy this thread, I hope you do.

Our Goals:

1. Learn more about ignition timing, timing advance, and it's impact on performance and fuel economy on a street car/truck.

2. Test common theories about ignition timing, ie lock out distributor, vacuum advance vs non vacuum advance, ideal total timing for a street 350 ci small block chevy (ie 32*, 34*, or 36* etc.).

3. Experiment, experiment, experiment with different advance [ahem] retard curves.

DISCLAIMER: This is not going to be about maximum power gains for a race car or a drag strip car, the test subject will be my daily driver 1974 GMC aka Chevy C10 (2WD) V8 350 with a manual 4 speed with overdrive transmission.

Questions / FAQ: here I will keep a real time list of questions, mine and yours

1. Is this ignition box EMISSIONS legal / compliant?

A. No, according to Holley's website: "This part is legal for use on Uncontrolled (Non-Emissions Controlled) Vehicles or Racing Vehicles."

2. Can I use my vacuum canister on my distributor with this box?

A. No, this and any other electronic MSD ignition requires you to lock-out the distributor, this locks both the mechanical and therefor vacuum advance. You can compensate for vacuum using a MAP sensor, more on this coming up, stay tuned.

3. Can I hook up a gauge directly to this box to see my timing in real time as I drive for example?

A. No, you need a laptop for that.

4. What is the maximum amount of retard this ignition box can pull out?

A. All of the retard amounts are cumulative and the maximum amount of retard is 30 degrees.

Resources:

Articles:

Going Digital: MSD Digital Conversion by Jeff Smith written in 2015 for Power and Performance magazine

Forums:

MSD 6AL-2 Programmable: Anyone Running Them? Aussie, Aussie, Aussie Gerg sets the record straight, by far my favorite write up, warning contains some profanity.

Videos:

MSD Programmable 6AL-2 review

I had my eye on this unit for a few years to be honest, but money and other priorities always kept it an arms length away... until this last Christmas...

brought to you by the same dude who posted: INNOVATE DLG1 Wideband O2 Oxygen Sensor Tuning Diagnostics Logging Air Fuel Ratio etc