Type of gas in a '66?

[65 Fastback]

Just curious as to what type of gas does one use in a 1966 Mustang 289 since there's no lead anymore? Premium? Is an additive still needed? THANKS!

[HidalgoGT]

Just curious as to what type of gas does one use in a 1966 Mustang 289 since there's no lead anymore? Premium? Is an additive still needed? THANKS!

If the motor was original never rebuilt I would run a lead additive as it wears the valve seats due to the way they were made back then and the lead wasn't as harsh on them. Least thats what I know of. Then they went to a hardened valve seat and unleaded gas. Though I could be wrong. Though no matter what year if it was carb'ed I ran the good stuff as the carbs seemed to like it better.

[PaxtonShelby]

In an older motor I think you should always run premium. You usually don't put many miles on a classic car, so the extra cost is negligible.

Engines that are made to run on unleaded gas have hardened valve seats. If the '66 motor never has not had hardened valve seats installed, it wouldn't be a bad idea to run some type of lead additive in the gas - maybe not every tank, but every other tank.

But chances are that the '66 motor has been apart in the last 25 years or so, and it is likely that hardened valve seats were installed. Ask the owner if he has any info or receipts.

How about some more info - do you have a specific car in mind, or are you just starting to look? Be prepared to shell out a bunch more $ for a '66 than you're getting for your '87. Early fastbacks are pricey these days - even if they need a lot of work.

[1Badbird]

My Dad has a 66 merc. cyclone gt with a 390 hipo and also a 67 ford fairlaine with a 289, he runs high test in them both. He's never used any additives and hasn't had any problems.

[65 Fastback]

In an older motor I think you should always run premium. You usually don't put many miles on a classic car, so the extra cost is negligible.

Engines that are made to run on unleaded gas have hardened valve seats. If the '66 motor never has not had hardened valve seats installed, it wouldn't be a bad idea to run some type of lead additive in the gas - maybe not every tank, but every other tank.

But chances are that the '66 motor has been apart in the last 25 years or so, and it is likely that hardened valve seats were installed. Ask the owner if he has any info or receipts.

How about some more info - do you have a specific car in mind, or are you just starting to look? Be prepared to shell out a bunch more $ for a '66 than you're getting for your '87. Early fastbacks are pricey these days - even if they need a lot of work.

I have seen several nice '65 and '66 Fastbacks in the low 20's. These aren't show cars, but nice "daily" drivers. Do you know of any good places to buy parts (Dallas Mustang?), and any good local mechanics? Thanks.

[HidalgoGT]

I have seen several nice '65 and '66 Fastbacks in the low 20's. These aren't show cars, but nice "daily" drivers. Do you know of any good places to buy parts (Dallas Mustang?), and any good local mechanics? Thanks.

Laurel Mountain sells just about any body/suspension/interior piece you could need. Mechanic wise there are several on the board to choose from.

[AdamantiumSilvr]

My Dad runs (Sunoco) High Test and a Turbo Blue race gas mixture in his 68' Charger R/T!

[map351]

I had a 65 Ranchero 289 Hipo 4 spd I drove it for over 13 years on unleaded fuel put over 90K hard miles never had the heads off still running today..

[somethingclever]

With a good tune I wouldn't worry about lead additive in this application.

With a high comp engine in a truck that see's high EGT's and possible lean conditions....now that's a different scenario.