Are you the original owner? Is it COMPLETELY stock or has it been rebuilt? If it has been rebuilt, what was changed?
Fuel is rated differently here in NZ. We have it listed by research octane number RON. I believe they use AKI (anti knock index) which is RON + MON (motor octane number) divided by 2 in the U.S. So RON ( NZ) AKI (US) 91 _________________87 95 _________________ 90~91 98 _________________93~94 With that said it comes down to what your motor will tolerate. The 300-2 stock as a rock motor in my 65 runs sweet on our 91 swill.
I’ll second the non-ethanol gas, especially if you don’t drive the car much. My 78 emissions clogged 350 seems to be Ok with 89 as well, although the only non-ethanol fuel here is either 91 or 94
Great information ! I've been running my GS on 91 and seems fine , I thought I would just check as it's been over 20 years since I've owned a V8 & wanted to make sure what other classic car owners where using . There was once concern though ! Do I need to worry about my engine/valves or will it be fine as mine my have hardened valves seats ? or is there an additive in our NZ gas to protect the engine ?. The car is not driven much & as far as I know its totally stock standard 1971 GS 350 4 barrel
[QUOTE="71 GS, post: 2995675,] There was once concern though ! Do I need to worry about my engine/valves or will it be fine as mine my have hardened valves seats ? or is there an additive in our NZ gas to protect the engine ?. The car is not driven much & as far as I know its totally stock standard 1971 GS 350 4 barrel[/QUOTE] It was always my understanding that the Buick heads were cast with a higher nickel content. Of course if the heads have had numerous valve jobs the valve seats may not be original. I would think you'd be ok.
It was always my understanding that the Buick heads were cast with a higher nickel content. Of course if the heads have had numerous valve jobs the valve seats may not be original. I would think you'd be ok. [/QUOTE] It was the removal of lead from gasoline that caused concerns about valve seats. Here in sunny Florida non-Ethanol gasoline is still unleaded. I don't know about NZ, but in many states (if not all) here in the USA, the only way to get unleaded gasoline is to bring gas cans to an airport and purchase aviation 100 LL. That is a major PITA, and a hell of an expensive way to fuel an automobile. If unleaded gasoline is a concern of yours, about the only practical solution is to use a lead-substitute additive to the gasoline.
It was always my understanding that the Buick heads were cast with a higher nickel content. Of course if the heads have had numerous valve jobs the valve seats may not be original. I would think you'd be ok. [/QUOTE] Thanks! great to know
I'm probably wrong about this, but it was my understanding that it was the 1975 and up engines that were designed to run on unleaded. 1975 was the first year of the Catalytic Converters that don't like lead. Did they start on unleaded engines four years before the Cats?
