Newbie needs 273 spark plug help

-
Ciguatera

Ciguatera

FABO Gold Member
FABO Gold Member
Joined
Apr 28, 2017
Messages
30
Reaction score
18
Location
Virginia
Hi,

I just joined FABO and posted a brief introduction in the Welcome Wagon forum. I'm very happy to be here and looking forward to learning from all the A body experts. I just bought a stock 1965 Barracuda Formula S with a 273 Commando and 904 automatic. This is my first technical question on the forum, and appropriately for a newbie, it's sort of a dumb question:

What spark plugs fit a stock '65 273 4bbl? It has the original 10.5:1 iron heads. I failed to find any plug specs in the service manual, though I'm sure it's there somewhere in the 700+ pages. When I enter the year make and model on car parts websites, I get all kinds of different plugs. Some are 3/8" reach (length of the threaded part of the plug), some 3/4". Heat ranges are all over the place. Some are even non-resistor.

I'm particularly concerned with the reach length. I have domed pistons and I'd like to avoid turning the Commando into scrap metal on start up!

Thanks in advance!
 
I run RN12YC Champions in my HP 273. I have had issues with Autolites in 2 different small blocks being too cold.
 
3/8 reach plugs are for big blocks. 3/4 reach plugs are for small blocks and slant sixes.
 
You will find that the parts counter books are pretty stupid regarding the 273-4bbl. So don't be afraid to ask more questions.

Just wait until you try to replace the points...
 
I have restored a lot of small block dual point distributors, about 3 years ago standard decided that small block and big block use the same points, I have sent them emails and talked to the sales people and nobody understands.
I have the part numbers so I just order the number and if the warehouse has them I get them, or maybe another store might have them, I know they are going extinct and I'm not sure we can fix it.
 
Thanks for all the plug replies. Good to know about the points too. I think I'm going to keep the mechanical ignition. Going by Toolmanmike's points thread, I guess I should get NAPA/Echlin CS721A points and several condensers in case I get a bad one. So much to think about!
 
Vqlt said:
I have pertonix igniter 2. Installed by techs at their San Dimas Corp office. Original prestolite distributor
Click to expand...
If you have the kit number please post it and I can add it to my thread for future reference. Thanks.
 
Rockauto will list most plugs which fit. Platinum or iridium should last longer, but I don't know if they work poorer with points ignition.

You can even get up-dollar points from Accel, but don't know if actually better. Main thing is to get a dwell meter so you can set the gap precisely. Feeler gages are just to get it close. Dual-point distributors are trickier to adjust (I never had one). Even then, points will never give as strong a spark as electronic ignition w/ an e-core coil. To best protect your engine, the Pertronix Ignitor III has a rev limiter, which might be especially important on your engine which can really spin up.
 
You must log in or register to reply here.
-

Back
Top