The difference in size is due to different
bore sizes, as well as different
stroke lengths on the crankshaft. The size on an engine is rated in cubic inches(or liters on newer engines). This is a combination of how many cubic inches measured in the bore, including the diameter of one cylinder bore, and the length of the piston stroke. That figure is multiplied by 8(on a V8 engine) to arrive at the final cubic inch rating.
(I don't have any
specific figures handy, nor am I intelligent enough to have them stored in my pea brain
)
The bore size is the diameter of the piston(plus a little for clearance), and the stroke is how far up/down in the bore the piston moves, which is a function of the crank.
A 355 is a 350 that has been bored(oversized) .030".
A 383 is a 350 that has been bored,
and has a special crank that gives it a longer stroke. This requires a special rod length, as well as some minor block grinding to clear the longer throws of the crankshaft.
The heads, valve size, and cam, have nothing to do with the cubic displacement of the engine.
Hope this helps some...
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Joel Adams
C3VR Lifetime Member #56
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