Which spark plugs do I run? 67 289K

rcgt350_old · May 27, 2008 at 1:49 AM

Ok guys, what plugs would you run? I'm ready to start my 67 289 K engine in my GT 350. The engine is all stock built, .30" over. I have Autolite BF32 plugs and Motorcraft BF42C plugs. Thanks Randy

Edited by - SixT5HiPo on 05/30/2008 22:07:55

BoS_old · May 27, 2008 at 6:13 AM

I have been running BF32's for over 30 years

in my 67. Worked fine at all times. Gapped them

at the recommended 0.028-0.032" until I installed

Pertronix, coil and ignition wires at which time

I increased the gap to 0.032-0.035"

/Bo

C6ZZKGT · May 27, 2008 at 9:24 AM Official Post

I have been using BF42's which are the equivalent of the BF42C Motorcraft that you have. They never foul and produce good plug readings for all of my driving. They are also expendable whereas your BF32 plugs can sometimes foul with around town driving and cost much more to replace.

-Fred-

rcgt350_old · May 27, 2008 at 10:28 AM

Ok, I have an old autolite spark plug guide book, it says .035 for BF32, should I go .032?

Maybe better to run in on the BF 42's until I get a few miles on the engine?

Randy

zray · May 27, 2008 at 2:38 PM

I use Autolite APP 45's. Long lasting, and haven't fouled one yet.

Z. Ray

rcgt350_old · May 30, 2008 at 10:16 AM

Well I ended up running the BF32 plugs and she runs real crisp and strong. Engine is just broke in so far, so will keep an eye on them to see show they fair. Randy

6hypo5conv_old · August 1, 2008 at 5:12 PM

I understand that the 43 year old BF32 plugs that are selling for sometimes BIG $$ will "blow out" as in blow the porcelan off?? anyone had this happen??

RalphJr · August 2, 2008 at 1:22 AM

Sold auto parts in high school and college - saw this happen a total of 2 times in about 7 years - I wouldn't worry. The plugs won't degrade and are crimped together - only if the crimp is bad would this happen.

I ran Autolite 45's in my HiPo for a number of years after the other plugs got hard to find - never fouled one either.

I've always tried to gap on the low side of the recommendation. The gap will increase as the plug ages and the tip erodes, so you stay in the correct gap range longer - just don't over do it.

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