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Droolguy · 09-15-2017, 02:15 PM

A TH400 has over 30% more transmission loss than a TH350, on a good day.

It's actually one of the least efficient transmissions in existence.

But yes, 10mpg in your exact combo with proper tuning should not be a problem.

09-15-2017, 02:15 PM	#21
Droolguy Registered User Join Date: Jan 2017 Location: La Pine, OR Posts: 35	Re: 73' Olds 455. A TH400 has over 30% more transmission loss than a TH350, on a good day. It's actually one of the least efficient transmissions in existence. But yes, 10mpg in your exact combo with proper tuning should not be a problem.