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Hi gents

Anyone who knows original spec for engine oil, transmission and rear axle?
It´s orginal matching numbers car with 400 (335 hp), TH400 and for the moment i cant remember which rear axle.

What type do you use?
10W40?
20W50?
High Zinc?

Best Regards
Marcus
 

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Hi gents

Anyone who knows original spec for engine oil, transmission and rear axle?
It´s orginal matching numbers car with 400 (335 hp), TH400 and for the moment i cant remember which rear axle.

What type do you use?
10W40?
20W50?
High Zinc?

Best Regards
Marcus
Factory recommended 20W oil above freezing or 10W-30 as an alternate. Automatic trans uses Dextron fluid. Manual trans - SAE80 weight. Rear axle - SAE80 weight, but requires additive #1050081 .

But, asking what oil is a loaded question. If the engine is stock, ie flat tappet camshaft, you need an oil with Zinc such as Brad Penn or Joe Gibbs or you can get a zinc additive. Some use the synthetic blends and say they are OK, but I have never used them.

Oil weight depends on outside temps, and engine wear as well. I would use 10W-30 as a minimum and might even opt for 10W-40 if it has miles on it and for hotter summer weather. 20W-50 is too thick unless you have opened up the clearances on your rod & main bearings - ala racing engine, and have the oil pump and aftermarket pump shaft to turn the thicker oil.
 
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