Fueling a Classic Bonneville

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AfterDark3

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I am working on restoring a 1965 Bonneville,389 with 4 barrel, 10.5:1 compression. One of my paramount concerns is fueling the thing. I have done a lot of searching and have yet to find a definitive answer. The question is not correct octane, I can get AKI 93 at a local Cenex, but the question is additives or no additives. I have heard all sorts of things, ranging from "Don't worry, the valve seats are already hard enough, you don't need lead/additives" to "You should run down to your local airport and fill up on 100 Low Lead" (which is technically illegal), with all things in between. Should I replace the valve seats? (which isn't cheap) or are they indeed hard enough to run Unleaded, or will a bottle of fuel additive per tank be sufficient to protect the seats? Or possibly a Mix of AVGas and Unleaded.
 
There is nothing that you have to do with regard to the valve seats. The whole valve seat thing with unleaded has become a myth. If you intend to tow trailers up mountains with your car by all means you need a lead additive. There are enough vintage cars running out there using 93 unleaded that have not had catastrophic valve seat failures that prove the point. I have a 69 Corvette with 11:1 compression, the engine has been apart twice since 1973, and the heads have had just surface milling so by now it is an actual 11:1 and the seats are fine. Does it run better with 100 unleaded or 110 leaded, yes, but cost, about $10/gallon isnt practical. Once it's running what you can try doing is filling up a 5 gallon container at the airport and adding 2 1/2 gallons to your tank with the remaining being the 93 and see if you notice a difference. Another source is the Sunoco web site and look at the link for racing gas. Most of the places do not use a pump but rather use 55 gallon drum that they can only pump into containers.
 
Thanks for all the info. Just another question, do you know of any information on GM's Transistor Ignition systems? I know this car has it because it is equipped with AirCon, is it something to get rid of, or keep? And if its worth keeping, how easy is it to fix/repair/tune? And if its not, can it simply be replaced with a regular distributor?
 
read this article and then contact the company to explore replacing the guts of the TI unit with more reliable modern circuits.

http://www.tispecialty.com/articles/article1.htm
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Are you sure the car has the optional TI Ignition? My old 65 2+2 had A/C and the standard Points ignition system.

From everything I have read the TI system is fine, it is just hard and expensive to get parts for. If it works I would run it, but have a Points or HEI conversion kit in the trunk if I traveled and distance beyond a Flat Bed truck ride home.
 
Actually after closer inspection, It looks like it was replaced with a standard Points system, after some other reading, it looks like many people replaced the TI system with standard points when something went wrong.
 
you thought because the car had air conditioning it had a TI system?
 
melsg5 said:
you thought because the car had air conditioning it had a TI system?
Click to expand...

At one point it did, there still is the hook ups for a TI system, plus the dealer manual stated that all cars with premium gas engines and AC systems had transistor voltage regulators and TI's installed. I presume at one point it was replaced because it became unreliable.
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