04-28-2023, 09:59 AM | #1 |
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R44 or R45S plugs??
Hi guys! My manual recommends R44 plugs for the 307 in my 69 C20. I'm running stock ignition with points. The parts store sold me R45S plugs for it. Is there any issue with that, or should I go back and get the 44? Thanks so much as always for your help!
Wes
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Found Grandpa's old '69 Chevy C-20 - It'll never leave the family again. "For just a little more, you can do it yourself!" |
04-28-2023, 10:11 AM | #2 |
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Re: R44 or R45S plugs??
The R45s is a hotter plug. My 327 burns oil so I changed from the R44 to the R45s to help from fouling the plugs.
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James 63 GMC V6 4speed carryall 65 chevy swb bbw V8 auto 68 K20 327/4 speed, buddy buckets 2002 GMC CC Dually Duramax 64 GMC lwb 3/4 V6 4speed SOLD 66 GMC swb bbw buddy buckets SOLD IG duallyjams The only thing that stays the same is constant change! |
04-28-2023, 11:14 AM | #3 |
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Re: R44 or R45S plugs??
It is hotter (as mentioned) and also comes with an extended tip ( S designation). What do the old ones look like? With todays crummy fuel I'd say stick with the 45s
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04-28-2023, 11:43 AM | #4 |
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Re: R44 or R45S plugs??
That's what I'm running in my 283
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67 C10 283 T5 swapped longbed fleetside = wife's daily driver 67 C20 292 (originally a 250)4speed longbed fleetside w/original wooden bed=my project truck 67 C10 283+.060 (so a 292 as well)T5 swapped longbed fleetside=my DD 72 C1500 Sierra Grande 350 TH350 longbed fleetside=wife's fair weather truck Can you tell we are fans of longbed fleetsides & 67s Chris |
04-28-2023, 12:06 PM | #5 |
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Re: R44 or R45S plugs??
I plan to pull them tonight and have a look at them. I have no idea what's in there and how old they are.
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Found Grandpa's old '69 Chevy C-20 - It'll never leave the family again. "For just a little more, you can do it yourself!" |
04-28-2023, 12:13 PM | #6 |
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Re: R44 or R45S plugs??
The extended tip plug came out in the late 50's early 60's for o-head valve engines. All the manufactures soon went with them. They are a big improvement from the recessed tip plugs. The R45S plug is only one step hotter then the R44. That is the best way to go. They should not be used in flathead engines.
George |
04-28-2023, 12:30 PM | #7 |
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Re: R44 or R45S plugs??
Just checked and I put Autolite 85 plugs in my '69 307 last time . Was that a bad choice ? Seems to run ok . Thanks !
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04-28-2023, 02:47 PM | #8 |
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Re: R44 or R45S plugs??
I used those in my 350 and they were good plugs ,I may switch back next time in my 327,Im running the 44 in them now.
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2001 Silverado K-1500 2005 FXDWG stage3 69 CHEVY Short/Step 327/4L60 373 posi 63 IMPALA 327 |
04-28-2023, 02:51 PM | #9 |
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Re: R44 or R45S plugs??
The R45S's should be fine in the 69 307 heads. The older motors tend to lose compression and use a little more oil so going one number hotter is probably a good move. I run the same plug in my 427 BBC w/69 closed chamber heads...I found some ACDelco R45S plugs on ebay for a $1 a piece. They were NOS plugs made in the US, they're not anymore. Hard to find US made spark plugs these days and when you do find them they're hot cheap! I'm running Pulstar plugs in my bike... http://toms427impala.info/CT/ACPlugI...Extended%20Tip
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American" |
04-28-2023, 03:45 PM | #10 | |
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Re: R44 or R45S plugs??
Quote:
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Found Grandpa's old '69 Chevy C-20 - It'll never leave the family again. "For just a little more, you can do it yourself!" |
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04-28-2023, 04:25 PM | #11 |
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Re: R44 or R45S plugs??
Thanks , Kaycee !!
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04-28-2023, 09:17 PM | #12 | |
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Re: R44 or R45S plugs??
Quote:
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Found Grandpa's old '69 Chevy C-20 - It'll never leave the family again. "For just a little more, you can do it yourself!" |
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04-28-2023, 09:45 PM | #13 |
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Re: R44 or R45S plugs??
Pretty sure that the product manufactured on different continents is going to be different. Might have not been the case in years past, but now, who knows?
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04-28-2023, 10:32 PM | #14 |
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Re: R44 or R45S plugs??
I doubt the difference in manufacturing plant will make such a difference as to be worried. You are going to have a bigger variance in cylinder compression and oil consumption and old plug wire in each hole than you are spark plug difference.
The plugs are not likely going to affect a 100 mile plug read. I would use what you got. Look them over at 100 miles and go from there. |
04-28-2023, 11:52 PM | #15 | |
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Re: R44 or R45S plugs??
Quote:
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American" Last edited by Ironangel; 04-28-2023 at 11:57 PM. |
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