THat 1974 GMC has a sticker in its door that says "This engine was designed to run on Unleaded Fuel with an octane of 91 or higher"
Just thought that was interesting....
Just thought that was interesting....
CK5
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While at parts yard 1974 GMC had a sticker
- Thread starter Chief Brody
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KansasTwister
1/2 ton status
THat 1974 GMC has a sticker in its door that says "This engine was designed to run on Unleaded Fuel with an octane of 91 or higher"
Just thought that was interesting....
the early 70s motor did not all have hardened seats in the heads. Suprised it had a 91 octane rating though. i run 87 in all my dd junk.
THat 1974 GMC has a sticker in its door that says "This engine was designed to run on Unleaded Fuel with an octane of 91 or higher"
Just thought that was interesting....
Could be that was research octane, not motor octane, and not the average we use these days:
http://en.wikipedia.org/wiki/Research_Octane_Number#Measurement_methods
The great thing about standards is there's so many (conflicting ones) to choose from.
Anyway, at the 8-10 split from the AKI or (R+M)/2 average we use now, that would be about 4-5 points lower, so your basic 87 octane now.
-- A
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The '73 Chevelle I swapped the 307 V8 from into my van,said the same thing on the radiator support sticker "Use leaded fuel of 91 octane or higher"...
I was kind of surprised to see that high an octane was reccomended--but then,even "regular" gas back then probably WAS 91 octane!..
I was kind of surprised to see that high an octane was reccomended--but then,even "regular" gas back then probably WAS 91 octane!..
i think you are right, because premium was 96 octane back then
