Camarocracy

I know you're not supposed to use 87 octane in the LT1, I use nothing but 93 and 94 for my car. But, when I purchased the car from the previous owner, she said she used 87 once in a while [she had other cars to drive, so I know this car was a good day driver. And I know the car was babied, was almost mint condition with only 29k on it]. I've since done the usual tune-up since purchase [new plugs, oil change, tranny fluid. Haven't gotten new wires yet since I'm waiting to get the OVC wires for the LT's].

When I drive the car, even when driving hard, I do not feel any loss of power or anything peculiar or weird sounds. Just wondering if there could have been any damage done to the motor from running 87 in it?

brians96Z

No.

IROC-T

If it runs on 87 and your not getting any knocking,then run 87 and save the change for performance parts.

Injuneer

If it runs on 87, you may not hear any knocking, but you are losing performance. It will be running with a lot of knock retard. And that is what protected the engine from damage when the previous owner used the low grade fuel.

RE AND CHERYL

The LT1 will run on 87 without hurting it. But it will be retarding timming due to knock, and therefor loosing power. I run 89 in my 94 and have no knock retard at all. I've verrified this several times with a scanner.

'86 350

Don't worry about it.