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Differences in Poly Transmissions

Here is the scoop; the 1956 to 1961 Plymouth Poly engines which includes Dodge except for the strictly Dodge 270/315/325 Poly's (able to convert to HEMIS) had and extended crankshaft flange with and eight bolt end where the studded torque covnertors bolted to the crank - just like the HEMIS.  This anomaly prevents using the modern LA aluminum caseTorqueflite trannys with these early Poly 318 engines without the special adapter sold by Wil-Cap and some other mfgrs.  Therefore, only the early cast iron Torqueflite transmissions made for these cars can be used.

Secondly, the bolt pattern on these 56-61 277/301/303/313/318/326 Poly engines is different than the later 1962-66 Poly 318 engines and thus all the LA engines.  The top four holes will line up but the bottom two holes on either side of the block, along with the dowel locating pins are different than the 62-66 Poly 318 engines and all LA engines.
Third, the starter location on all the aforementioned Poly engines is different, positioned approx.between four and five o' clock vs. the 62-66 Poly 318 engines and all LA engines.  The 62-66 Poly 318 enignes and all LA engines starter location is closer to the block; approx. the five o' clock postion.
Therefore, if you have read the info. carefully you will correctly deduce that the bellhousing pattern on the 1962-66 Poly 318 engines is the same as all the LA engines (273/318/340/360) into the early seventies* except for one lower bolt hole/driver side on the Poly is not found on the LA; this is not a compatiblity problem and the transmission will still mate and function correctly. The "missing hole" can be drilled into the late model case is you like.
The 1962-66 Poly engines can use the same aluminum case Torqueflite transmissions as the LA engines because their bellhousing pattern is the same except for the *one bolt hole difference.
1962 was the first year for the aluminum case Torqueflite and all the 62-65 Torqueflites had two pumps vs. the 66 and later with one pump.  Additionally, the spline count was 18 on the input shaft for these 62-65 Torqueflites and the later Torqueflites, 66 & up had a 23 count fine-splined input shaft
which is easily swapped into the 62-65 earlier trannys so one may use the plethora of modern convertors. 
Spread the word.
Gary Pavlovich

Thanks to Chuck Lowe of Moparfins and Gary Pavlovich.          




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