What was the last year that slant sixes had forged cranks? Just curious.
Forged crank /6s
- Thread starter niceolddart
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Slant 6 Performance Information - Parts and Pieces
"B. Crankshaft
Each engine has a different crank. The 170 is PN 2843941, the 198 is PN 2951979 and the 225 is PN 2899582. They all have the same main bearing journal diameter of 2.750" and also the same crank pin diameter (rod journal diameter) of 2.189". They also all have four main bearings. While the 225 crank will fit in a 198 engine (with the correct rods), the 225 crank will not fit in a 170 engine - it interferes with the block. The 1976-77 forged crank for the 225 is 3830099, while the cast crank is 3751036. The cast crank is not interchangeable with the forged crank. The forged crank was phased out of production at the end of 1976. The cast crank engines can be identified by an "E" stamped next to the engine number (i.e. 225E).
The best crank to use for heavy duty six cylinder applications with the 225 engine is the 225 truck crank which is shot-peened. The number for the trucko crank is 2899582 (with pilot bushing).
In 1968 the slant six's crank flange was changed. The flywheel pilot and torque converter nose diameters were enlarged on the newer cranks. These cranks are interchangeable except for this. The '68-69 large pilot crank for the 170 engine is PN 2843941. The 198 and 225 listed above are large pilot cranks.
The flywheel-flex plate attaching bolt pattern for the six is unique. It has six bolt holes, but they are located in a different pattern than the "A" or "B" engines."
"B. Crankshaft
Each engine has a different crank. The 170 is PN 2843941, the 198 is PN 2951979 and the 225 is PN 2899582. They all have the same main bearing journal diameter of 2.750" and also the same crank pin diameter (rod journal diameter) of 2.189". They also all have four main bearings. While the 225 crank will fit in a 198 engine (with the correct rods), the 225 crank will not fit in a 170 engine - it interferes with the block. The 1976-77 forged crank for the 225 is 3830099, while the cast crank is 3751036. The cast crank is not interchangeable with the forged crank. The forged crank was phased out of production at the end of 1976. The cast crank engines can be identified by an "E" stamped next to the engine number (i.e. 225E).
The best crank to use for heavy duty six cylinder applications with the 225 engine is the 225 truck crank which is shot-peened. The number for the trucko crank is 2899582 (with pilot bushing).
In 1968 the slant six's crank flange was changed. The flywheel pilot and torque converter nose diameters were enlarged on the newer cranks. These cranks are interchangeable except for this. The '68-69 large pilot crank for the 170 engine is PN 2843941. The 198 and 225 listed above are large pilot cranks.
The flywheel-flex plate attaching bolt pattern for the six is unique. It has six bolt holes, but they are located in a different pattern than the "A" or "B" engines."
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