--> All 1963 Cadillacs used the 2 bolt Hydramatic (HM) starter that was used from 1961 to 1964.
--> There were two starters used in 1964 due to the use of the newTurbo Hydramatic (THM) transmission on DeVilles, Eldos and Fleetwood 60S, and the adaptor ring required to mount the "Buick Borrowed" THM transmission to the 429 engine block.
--> The 2 bolt HM starter was used from 1961 to 1964 (parts group 2.041 part # 110 7387)
--> The 3 bolt THM starter used in 1964 was only used in 1964 for THM equipped body styles, and 1965 75 series (part # 110 7368)
--> In 1965 Cadillac got its own THM transmission with reshaped bell housing that mounted directly up to the back of the 429 engine block. Another starter (part # 110 8381) was used for 1965 except 75, all 1966, and all 1967 thru 1969 except eldo according the master parts book.
--> To reduce torque on the cast iron adaptor ring (prone to cracking), the 1964 THM starter used a rear brace to secure the starter to the engine block. It attached to rear of starter and bottom of engine block via two longer oil pan bolts and a spacer underneath to compensate for height of oil pan outer lip.
--> Also, due to change in right hand exhaust manifold from one that attached to exhaust Y-pipe in center in 1963 to one that attached in rear in 1964, a small bracket was used in 1964 to hold the battery cable next to the engine block.
Below are pictures including: 1964 THM starter on left and 1961-1964 HM starter on right; the rear brace used on 1964 THM starters, and the battery cable bracket used on 1964 engines.
Starters Used in 1963 and 1964
by Jason Edge
Aug 8, 2013
--> All 1963 Cadillacs used the 2 bolt Hydramatic (HM) starter that was used from 1961 to 1964.
--> There were two starters used in 1964 due to the use of the newTurbo Hydramatic (THM) transmission on DeVilles, Eldos and Fleetwood 60S, and the adaptor ring required to mount the "Buick Borrowed" THM transmission to the 429 engine block.
--> The 2 bolt HM starter was used from 1961 to 1964 (parts group 2.041 part # 110 7387)
--> The 3 bolt THM starter used in 1964 was only used in 1964 for THM equipped body styles, and 1965 75 series (part # 110 7368)
--> In 1965 Cadillac got its own THM transmission with reshaped bell housing that mounted directly up to the back of the 429 engine block. Another starter (part # 110 8381) was used for 1965 except 75, all 1966, and all 1967 thru 1969 except eldo according the master parts book.
--> To reduce torque on the cast iron adaptor ring (prone to cracking), the 1964 THM starter used a rear brace to secure the starter to the engine block. It attached to rear of starter and bottom of engine block via two longer oil pan bolts and a spacer underneath to compensate for height of oil pan outer lip.
--> Also, due to change in right hand exhaust manifold from one that attached to exhaust Y-pipe in center in 1963 to one that attached in rear in 1964, a small bracket was used in 1964 to hold the battery cable next to the engine block.
Below are pictures including: 1964 THM starter on left and 1961-1964 HM starter on right; the rear brace used on 1964 THM starters, and the battery cable bracket used on 1964 engines.