351C 4V Spark-plug wire question

Reply Subscribe

Thread Tools

Search this Thread

Jul 11, 2008 | 01:50 PM

abelmoreno

Thread Starter

Senior User

Joined: Feb 2004

Posts: 236

Likes: 0

From: Guayaquil

351C 4V Spark-plug wire question

Hello guys,
Would you please tell me thew spark plug gap I should set my plugs to?
I've got a 1973 351C 4V with an HEI distributor (coil on cap - chevy style) Taylor 8mm Hi-Energy cables & Autolite AP25 plugs.

Thanks

Jul 12, 2008 | 09:46 PM

grclark351

Posting Guru

Joined: Dec 2002

Posts: 2,003

Likes: 2

From: chicago burbs

i'd go .040"

Jul 13, 2008 | 03:01 AM

hollenjoe

Posting Guru

Joined: Jul 2007

Posts: 1,355

Likes: 1

every ford engine ive checked on nappas store on s plugs gaps says 0.040"....

Jul 14, 2008 | 09:14 PM

abelmoreno

Thread Starter

Senior User

Joined: Feb 2004

Posts: 236

Likes: 0

From: Guayaquil

Thanks a lot.
Won't the HEI dizzy make a difference? Or 0.40 is what you recommend considering the dizzy already?

Jul 14, 2008 | 09:23 PM

grclark351

Posting Guru

Joined: Dec 2002

Posts: 2,003

Likes: 2

From: chicago burbs

it's a dependable gap, a little more than the common .035" for points, and with the HEI it should never miss a beat. of course you can always try .045" but make sure your plug is capable of that gap without bending the electrode at an angle to get it. there are different plugs specifically for wider gaps, the electrodes are longer and don't need to be mis-shaped.

extended tip plugs are usually designed for the wider HEI gaps.