Torque Converter Design Change


New Member
Jun 9, 2020
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Can someone define the difference between the T.C.'s installed beginning in 1977, compared to the 1976 and before?

My concern is the thickness of the 4 Mounting Pads. 1976 has THICK pads and 1977 has THIN pads. I understand all the 'Balance Weight' issues, that part is simple. My question is the Interchangeability of the 76 back with the 77 up non lockup converters.

To clarify, I'm not referring to 'Lock Up' 23 spline versus 'Non Lock' 24 spline.

Thanks for help!
Was there a change in the front pumps?

Not an bear that in mind firstly.

I've interchanged "early" torque converters onto non lockup trans' at least until 1978 with no issues, meaning '67 and later 24 spline units. What matters is the plane of the pad mounting surface in relation to both the crank hub and the oil pump drive, which is something that is partially dictated by the flex-plate itself.
The factory service manual calls for the torque converter to be installed in the transmission fully engaged. Once the bellhousing is then bolted up, they specify a clearance between flex-plate and those thick or thin mounting pads, approx. a 1/4" inch. as long as it's there.... not tight, and not off by a bunch, then you are there, no problems.

HTH, Lefty71