We need more info. Is it a lawn mower, and flathead, hemi, airplane, spaceship, UFO ???????? Fill us in give us more details and pictures of engine if you have any.???????
Well first you have to figure out what size you need The decide if you need a pipe plug, spark plug or wood plug or ?? Spark plug you would first look up the application to get the correct size and then figure out if you needed a different heat range than the standard heat range. Then you decide if you want the basic old spark plug or a high zoot one made out of rare metals of some sort.
Sorry. BBC, 454, 600 CFM Quadrajet, Going in a '42 ton an a half that will be weekend driven for showin' off. Need it to be dependable. a larger carb may be installed at a later date. 750 would be the max.
I figured that but vague questions get off the wall answers if they get an answer at all. What engine, what heads and cam and what not and have you looked to see what the standard plug and heat range are for that engine already? Most of the time the standard recommended heat range for the engine works fine in what ever level of plug you feel like putting out the coin for. Special conditions call for different heat ranges and some brands seem to work better in some brands or models of engines than other brands.
so, what spark plugs are in it now? burning clean? running headers? stock motor? show motor ID numbers - will help to know year, etc
Other than oval port Tall deck heads, I know nothing about the motor. It was left in a field with the carb off an a wood rat decided to make a home in the intake manifold. I stripped it down to a short block, cleaned it up, re-gasketed it and put it on a test stand. Befofre running it, I did a compression check and found 2 dead cylinders (4 an 6). I was able to get one back somewhat to 90 PSI, but the other was kaput. Pulled the heads and for the first time in my life,.....I paid 380.00 for my first head job. Pun intended. 5 bad exhaust valves and 2 bad intakes. Stock motor as far as I know. There were no markings or stampings on the Timing chain side of the cam nor on top of the pistons.
Champion RBL9YC , to RBL12YC. The 9 is a little cooler heat range, suited to "high performance driving" including towing. While the slightly hotter 12 is intended for more lite throttle, stop and go city driving. Equivalents are AC R42T, R42TS Autolite #23 Or so I hear.
Hotter plugs have a longer tip on the insulator. They run hotter and burn off deposits, important for cars that are lightly loaded, 'loafing' and driving in traffic that never get very hot. Colder plugs have a shorter tip, they don't burn up in heavy duty use like in a big truck carrying heavy loads up hill or on the Interstate. The factory recommended plug is a good compromise worked out for your engine/vehicle after exhaustive tests. I would start with whatever plug GM recommends for a 454 in a truck your size, in your year of engine. If they foul up all the time go hotter, if they burn up go colder. Most likely they will work fine.
If you mean it's a tall-deck block, look for plugs for a medium duty Chevy truck like a 50 or 60 series. That should get you a good starting point. Did this engine have 4 ring pistons or was the intake set up for dual thermostats? That's a couple of signs it's a tall-deck medium duty engine.
I don't think they ever made a 454 medium duty tall-deck engine. >edit: My mistake... They DID make a tall-deck 454 also.< More than likely it's either a 366 or a 427. Try starting off with an AC R42T or R43T spark plug. Best to start off on the cool end of the scale.
I would start out with AC sparkplugs that GM recommend for a passenger car BBC, lower HP engine late 60's early 70's, factory engineering is good/great, for most anything street driven IMO. Take a plug with you, for cross reference, thread size, seat type and I'm not familiar with truck engine. Hopefully you have a parts store that has someone over 18 w/ some knowledge and will take the time to look up and compare the different spec's, truck versus car, that's the heat range mentioned here.
Casting # 14015445...454.......75-87...truck light duty light duty plug is R45TS heavy duty plug is R44T
I never use Champion! It is the only spark plug that I have had just fail. I use A/C in Chevy's/ GM's and Autolite in Fords. That's my story and I'm sticking to it! As far as what number depends on what exactly you are running. Best to start with what the engine calls for.
The Jalopy Journal
