Gas for 327

[Red69stepside]

What grade of gas should I put into a 327 in a 69 step?

PO said he used hi test, but he has a beter job than I do.

Would regular be ok?

[67cst]

ive got a 327 and i also run the high octane, it runs best with it i find

[Longhorn Man]

run your tank down to almost empty and put in 5 gallons of 87 octain, then drive it hard, and make sure you drive it in the hottest part of the day with the cheap fuel too, if you hear pinging, then you'll either need to tune for teh cheap fuel (back down the timing) or jo up a grade in fuel.
Only put in 5 gallons or so, that way if it sounds like you have marbles in your cylinders (lots of detonation) then you can pour some 92 on top and not kill your pistons/rods.

[chevymad]

My 68 250hp 327 likes plus grade or better. 87 pings terribly.

[70short/step]

My 327 runs great on the lower grade fuel. I usally run Cheveron regular grade. But every now and then I go to Safeway and run thier lower grade fuel also and it still runs fine. My 327 has high lift cam, aluminum intake with holley 600cfm, headers and auto 350. You should run the lowest grade fuel you can without pinging and pre-deetionation. It isnt benifical to your engine or your pocket to run high grade fuel if it doesnt need it.
70short/step

[cochran63]

I have a flat topped 327 in my 85. It has some 461x double humps with 2.02 stainless valves. I have ran it on 87 and 91 but it seems to run smoother and get better gas mileage with the 93.

[MandarinSixSeven]

I tried the high octane last week it made my truck pop out the exhaust like crazy, I was in a panic trying to figure out what it was, then as soon as I got some 87 octane back in there and run through it, its fine. I think its basically just choose one and stick to it.

[jmanz69]

When my 327 was still together and running, I used to have to run premium. It was high compression (11.5:1 with 58cc heads), and would diesel without it. It could go on midgrade, but would ping pretty bad if I got on it. Lowgrade was out of the question. Your engine depends on how it was built. If it was fairly stock, then you can run low or midgrade - whatever doesn't ping. If it's been built for more HP, then you will probably need higher octane. If you can find out the specs on how it was built (compression, cam specs, piston type, head type) then we can help more. 327's can be built in 100 or more different configurations, and just saying it's a 327 doesn't really help. I would do like what was said before, try the cheap stuff on an empty tank and see how it runs. If it's good, then just keep buying the cheap stuff. You will probably notice a very small performance decline, but it shouldn't be too bad.

[thisolechevy]

I just use regular cheap pump gas in my '68 327 and runs great!! It has all edelbrock from the block up. Intake, cam, heads, pistons, rods, everything 650cfm performer carb. I run low 14's high13's with it so no problems there.

[Fred T]

We had a 327 in our 63 Bel Air. Had to run ethyl (hi octane) or it would knock. Compression was around 11:1. I know the later engines had lower compression. I suggest you follow longhorn man's advice.

[Red69stepside]

I'm a little over my head here on these compression spece, but I know the compression guage read between 160 and 180 when it was tested.

The PO has gone off to a better life (UNC football) and isn't interested in digging up specs for me.

I'll try the cheap stuff. See what happens.