Octane
 

What octane are you using and why? Stock motors only please. Remember these pumps? You just put the slider on the octane you wanted. A little ping try the next one up. I remember buying gas on these. Bought a dimes worth to get home with my 348 and 3 two barrels. Times were tough!

Re: Octane
 

Reminds me of this pump at a station I stopped at, had never seen 1/2 octane values.

Re: Octane
 

hi guys, 87 octane. gm goodwrench crate engine, were rated at 8.5 comp but were more like 8.0 comp or less. works perfect. chuck

Re: Octane
 

I run 91 no Ethanol, listed here as "recreational" gasoline. 1980's 454

Re: Octane
 

I run non-Ethanol 91 octane in all my hot rods and small engines. My hot rods go in the shed mid-October? and they don't come out until April. Never had a problem starting them in the spring. But keep in mind we don't put a lot miles on them so the extra cost for 91 octane
is minimal.

Re: Octane
 

1967 GMC 250 L6…owner’s manual recommends regular gasoline (which was about 94 octane back then and of course leaded)…I use non-alcoholic gasoline which around here is typically 92-94 octane…it’s expensive, but my truck isn’t a daily driver and my hearing probably isn’t good enough to hear the engine pinging if the octane is 87-89, (if indeed pinging occurs….)

Re: Octane
 

When I was building up a 292 for my '68 C/10 Stepside, the Machinist asked what compression I wanted. 8 to 1, I said, so I can use the cheapest pump gas available. I think he was used to most of his Hot Rod/Racing customers wanting higher compressions.

I had a 454 BBC in my '67 K/10 Suburban. It required 91 octane, and a lot of it. Chevron Regular [87] ran OK, but other brands had to be Supreme.

I was running the Mr Goodwrench 350 in my '71 GMC Jimmy on 91 octane for years, until last year, when Regular jumped up to $5/Gallon. Then I put it on an 87 octane diet. After a carb adjust, it runs fine on Regular.

Re: Octane
 

My stock (rebuilt) 350 is happy with 87 octane.... as long as you give it plenty of the stuff.

Re: Octane
 

I run non-ethanol in my truck and get either 87 or 91 octane, depends upon the station. Closest has only 91 with no corn but one a bit further out I can get 87 without ethanol.

Runs fine on both but the 87 is a little less costly. Mine is not a daily driver either so I don't mind paying up for the non corn version.

Re: Octane
 

Back when my 70 Blazer was a daily driver, I would run 89 octane and it never complained. When I get it back in operation, I will use the 90 octane Rec fuel IF it's still available.

Re: Octane
 

87 Octane refilled every two days. No way I could afford 91 octane. No complaints from either one of my trucks.

Re: Octane
 

Wife' car = 68 Chevelle, stock 327 w/HEI. Runs fine on 87 pump gas.
My truck = 70 GMC, stock 396 w/HEI. Runs fine w/the same.
Actually, all my toys run on the same until hibernation.
Then they get non-alcohol, usually 93, w/2x seafoam package directions.

YMMV...Don.

Re: Octane
 

My Blazer has an L31 running right around 9.7:1 compression, Quadrajet, and Progression Ignition HEI distributor. I run 87 octane in it.

I have two Z/28s and they get premium.

Re: Octane
 

My truck tolerates 87 for normal use, but I put premium in it when towing. Now that I don't use it for towing, I'll start using 87 all the time.