I have accumulated (5) 'long-tail' TH400s and they are talking up way too much room. I have a tentative agreement for a semi-local trans shop to buy my excess surplus. But before I grab 'n go, I am wondering if there are any advantages/ differences I might not know about. Here's what I have: (2) '65 Pontiac TH400s (1) '66 Pontiac (GP) TH400 (1) '70 Buick (Electra) TH400 (1) '72 Buick (Riviera) TH400 The 455 from the same '72 Riv is going into my Buick, so I was leaning towards keeping the '72 TH (it ran the most recently). Any words of wisdom??
The 64-70 TH400's have the sprag 3rd gear clutch drums (assuming no one changed them) which can be upgraded from a 16 element sprag to a 34 element HD sprag. Most 71 on up have a roller type setup which can't use the HD type. Hope this helps. Mark
The late 60s and 70s cases with visible gussets in the bellhousing area are stronger. They are usually long tails. The center support was improved around 70 also. Keep the direct drums from the 70 and earlier units. Then use them in the 70 and newer cases.
