318LA Myth's still being created!
Early (pre-62) 318 poly motors with the 8-bolt extended crank flange didn't use a flex plate. The torque converter bolted directly to the crank, with the bolts inserted from the front into the crank flange and then into the converter. Trans had a separate bellhousing and main trans body. So, to put it all together, you bolted the converter to the crank, then bolted the bellhousing to the engine block, then slid the trans into the bellhousing, making sure the input shaft went cleanly into the torque converter, then, once in, you bolted the trans to the bellhousing. And yes, I did all that when I rebuilt the Powerflite trans in my 56 Plymouth.
BTW, Dodge and Chrysler poly motors of the fifties were just early hemi motors with poly heads. But the Plymouth poly (which the 318 originally was) was an all new motor that ultimately developed into the 273-318-340-360 LA wedges. Same bore spacing, same cam to crank distance, timing chains and distributors are interchangeable between A and LA - all years. The 277 in my 56 Plymouth looks just like a 318 poly, but has smaller bore and shorter stroke. 57 was the first year for the 318. There were also the 303, 301, 313, and 326 (59 Dodges only) - all A motors.
Edit: Just to clarify (or confuse) - 55 Plymouths V8's had smaller cubic inch versions of the Dodge poly motor. So did low line 56 Plymouths except those with power pack (4 barrel carb, dual exhaust). And low line 57 DeSotos (i.e. Firesweeps) used the largest version of the Dodge poly motor (325).
56 277 poly
The back side of the pre-62 318 poly motors is different than the 62 and later, and the bellhousing bolt pattern is different. Cranks and automatic transmissions are not interchangeable between early and late. Neither are manual transmission bellhousings and flywheels (manual transmissions themselves may be may be with the correct bellhousing and flywheel, not sure). However, ALL Plymouth poly motors, early and late, in all the cubic inch versions, used forged cranks.
pre-62 318 poly rear of the block
62 and later 318 poly rear of the block - notice the lack of ribs in the back of the later block
Early (pre-62) 318 poly motors with the 8-bolt extended crank flange didn't use a flex plate. The torque converter bolted directly to the crank, with the bolts inserted from the front into the crank flange and then into the converter. Trans had a separate bellhousing and main trans body. So, to put it all together, you bolted the converter to the crank, then bolted the bellhousing to the engine block, then slid the trans into the bellhousing, making sure the input shaft went cleanly into the torque converter, then, once in, you bolted the trans to the bellhousing. And yes, I did all that when I rebuilt the Powerflite trans in my 56 Plymouth.
BTW, Dodge and Chrysler poly motors of the fifties were just early hemi motors with poly heads. But the Plymouth poly (which the 318 originally was) was an all new motor that ultimately developed into the 273-318-340-360 LA wedges. Same bore spacing, same cam to crank distance, timing chains and distributors are interchangeable between A and LA - all years. The 277 in my 56 Plymouth looks just like a 318 poly, but has smaller bore and shorter stroke. 57 was the first year for the 318. There were also the 303, 301, 313, and 326 (59 Dodges only) - all A motors.
Edit: Just to clarify (or confuse) - 55 Plymouths V8's had smaller cubic inch versions of the Dodge poly motor. So did low line 56 Plymouths except those with power pack (4 barrel carb, dual exhaust). And low line 57 DeSotos (i.e. Firesweeps) used the largest version of the Dodge poly motor (325).
56 277 poly
The back side of the pre-62 318 poly motors is different than the 62 and later, and the bellhousing bolt pattern is different. Cranks and automatic transmissions are not interchangeable between early and late. Neither are manual transmission bellhousings and flywheels (manual transmissions themselves may be may be with the correct bellhousing and flywheel, not sure). However, ALL Plymouth poly motors, early and late, in all the cubic inch versions, used forged cranks.
pre-62 318 poly rear of the block
62 and later 318 poly rear of the block - notice the lack of ribs in the back of the later block
