455 Spark Plug Gap

**Ashauer** · 07-18-2006, 08:01 PM

I was wondering what the original spark plug gap is for a 455 Buick that has 10:1 compression. I'am running AC's R46TS spark plugs.

**bobc455** · 07-19-2006, 04:23 AM

Originally Posted by Ashauer

I was wondering what the original spark plug gap is for a 455 Buick that has 10:1 compression. I'am running AC's R46TS spark plugs.

Points or HEI? Makes a difference.

Also, I am surprised you are running the 46 plugs, I would think they would be a bit too hot for a 10:1 engine. I think the 45s are a stock heat range.

-Bob Cunningham

**rcull** · 07-19-2006, 05:08 AM

This may help:

http://www.buicks.net/shop/tuneup.html

**Ashauer** · 07-19-2006, 05:23 PM

I think your right about the 45's being stock, anyways I'm running a electronic box from Mallory with a Mallory Unilite Dist.

**Jim Carmichael** · 07-20-2006, 08:45 AM

If your running that box use a set of plugs for a latter 455 with .80 gap. You can set the 45 to .80 but it will have the wrong angle and won't have the right heat range.

**sicksteve** · 08-07-2006, 08:18 PM

0.060" stock for HEI. 0.045" points

With an aftermarket coil, ignition module and spark box, It can be higher, depending on other enginemodifications.

I put an accel Brute force HEI in cap coil, an accel ultra high-current ignition module and 300+ low-resistance wires on my '76 455 (8.5:1), still experimenting--started at 0.070"

In my '73 455, I'm just putting in an accel Billet-proof electronic dist. (with the same ignition module as above) an external jacobs "ultra coil" and low resistance accel 8.8mm plug wires. 0.070"?

I thought R45TSX were the right plugs. On later Buick engines with tighter emission controls (like my dad's '79 X-code 350 V-8, it took R46TS plugs).