Stock distributer cap upgrade 76 to a 78

[tampabronco]

Need to upgrade to 8.5 mm plug wire to support the Holley Sniper EFI in my 76 bronco 302. Have read that it's easier to get a cap adapter, distributer cap & rotor from 78/79. I' already have a set of HEI/male (my 76 cap is female) plug wires that would fit the 78/79 cap. Has anyone gone that route or would I be making a huge mistake?

 

[DirtDonk]

tons of us have done it. Not sure why it would be any kind of mistake as it's just 'better" in general for electrical performance.
Not to mention easier to keep this type of wire end from pulling apart in the distributor cap!

I think a '76 should already have had the large cap. Maybe a PO changed it out when they could not find a correct replacement? It's all backward or forward compatible either way.
Since you already have the correct newer style wires, I say go for it.

Paul

 

[savage]

I converted 74 to the new style cap and rotor, easy job .

 

[tampabronco]

Got it changed out and then realized my coil plug wire doesn't fit my new distributor cap.... Always something

 

[tampabronco]

tons of us have done it. Not sure why it would be any kind of mistake as it's just 'better" in general for electrical performance.
Not to mention easier to keep this type of wire end from pulling apart in the distributor cap!

I think a '76 should already have had the large cap. Maybe a PO changed it out when they could not find a correct replacement? It's all backward or forward compatible either way.
Since you already have the correct newer style wires, I say go for it.

Paul

Have a MSD coil and upgraded distributor cap... What plug gap should I go with? 35? 40?

 

[DirtDonk]

What was the original setting for a 76? Wasn’t it about. 042?
And just to be sure, your distributor is Dura Spark and somebody didn’t swap in an old point‘s type. Correct?
With a stock ignition, even with upgraded coil, and stock cylinder heads, I would just use the normally recommended plug type and gap.
At least as a starting point. See how it works.

 

[Broncobowsher]

Got it changed out and then realized my coil plug wire doesn't fit my new distributor cap.... Always something

When I get the motorsports wire set it comes with both styles of coil wire.

 

[tampabronco]

When I get the motorsports wire set it comes with both styles of coil wire.

I should have said it was too short. I mounted my coil on the firewall to get it away from the holley sniper ECU.. I was able to scrape one together

 

[tampabronco]

What was the original setting for a 76? Wasn’t it about. 042?
And just to be sure, your distributor is Dura Spark and somebody didn’t swap in an old point‘s type. Correct?
With a stock ignition, even with upgraded coil, and stock cylinder heads, I would just use the normally recommended plug type and gap.
At least as a starting point. See how it works.

It's the duraspark. This will be the first spark plug change since I installed the Holley Sniper. Kinda interested see how they look

 

[DirtDonk]

Spark gap is all about the ignition energy available, the combustion chamber shape, induction and exhaust, and not least of all what cam.
If it’s a stock motor then stock gap is a great starting point. Even with certain ignition upgrades that would allow you a few more thousandths of gap, it often still runs better at the factory setting.