1969 T-bird 429 oil type

[Alec5055]

New 1969 T-bird 429 owner here looking to do my first oil change. What type of oil is recommended? Does it need to be high zinc? The car has 55k miles and I drive it gently two times per month.

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[Alec5055]

Also, the engine is all original and we live in California with very mild weather. The classic car shop I took it sadly went out of business.

 

[Dozertech]

I use 5w30 regular oil. I wouldn't recommend ever using synthetic with the old cork gaskets. As long as it has the api circle on it you should be fine. You can use zinc additive if you like but your cam should be well enough broken in to not have to worry too much about the zinc.

 

[64ZCODE]

Hi there. I use Mobil 1 15W/50 full synthetic. I disagree that synthetic oil leads to oil leaks, and believe the benefits of reduced friction, longer engine life, and more duration between oil changes are well worth the added cost of a synthetic. The higher viscosity will provide more protection to the engine at running temp. These old FE engines have plenty of clearance so no need to run low viscosity oil.

More on synthetics: a few years back, Mustang and 5.0 Magazine reported on before and after dyno results for a 5.0 motor converted from regular to synthetic oil. Dyno results confirmed an average 5 HP increase at the rear wheels for synthetic oil, proof positive of less friction in the engine. What could be better than that?

 

[OneAmongOthers]

429 is a 385 series engine not FE. My oil choice is 10w30 for summer and 10w40 for winter. Zinc I would defiantly say do it. It's not for just breaking in the cam, but it provides more cushion for the older flat tappet lifters on the cam lobes so you don't wear them down. I would also recommend adding a bottle of Marvel Mystery Oil with every other oil change, and add a bit into your fuel tank as well on each fill up. Been doing that in my engine and she runs great. As for synthetic? Well I don't see a problem using that over conventional oil. Synthetic has less harmful byproducts than conventional fossil oil's It's been more refined to last longer too. Though I would recommend running the car more than two times a month. You don't want today's gasoline sitting in your tank or carburetor. What with the shoot ethanol added to todays gasoline its really does a number on the internal components of your carburetor and fuel lines.