Same thought here, they sure used some strange nomenclature. Poulan aficionado ModifiedMark may have some better insight on this.
The cubic inch displacements (3.6 & 4.5) of those two saws are somewhat incorporated into their model numbers, but not in the same way. I remember that the early 306 saws had a “Thirty-o-Six“ script on the clutch cover label. See the attached picture (copied from an old 2011 Ohiogregg post) with full Garand chargers below.
They kept the 245 as a 200 series saw, & then assigned the 306 to a 300 series. Not sure why though, but it could have been a marketing call as they already had used up model numbers 360 & 361. The 306 & 245 shared a lot of parts except crankshafts, rods, top handles, top covers, top end parts & wrist pin/bearings.
The older Poulan 360 & 361 model have the same cuin as the 306 & even used the same piston & rings.
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