All the 3400 Poulan branded saws in Canada that I've seen have the 3700 cover, also called a winter cover.
I measured the difference in open area between the rear slot units and the comb on the inside of the standard cover and the difference is small. I would guess that they made that change to try to get less crap into the filter but I can't see any difference in that respect.
I measured the difference in open area between the rear slot units and the comb on the inside of the standard cover and the difference is small. I would guess that they made that change to try to get less crap into the filter but I can't see any difference in that respect.