Join Date: Jan 2002
Location: Grand River, Ontario
There are so many variables here that it's hard to say yay or nay.
As an example, a few years back I had two clients with high end switch rods, both of whom were having difficulty fitting lines to their rods. It turned out that their rods had a very narrow window. Thirty grains over was enough for the rods to be over loaded and very hard to cast well.
On the other hand, my current switch rods accept a very wide range of lines and I can pile on the grains with nary a whimper.
Casting stroke has a lot to do with it as well. A while back, just to prove a point, I double hauled a 450 grain Scandi head on a 9' 5 wt. PRO4x trout rod, sending it a measured 90'. Would I fish that combo? Never, but it did prove that given a good rod and an adjusted casting stroke, ridiculously heavy lines can be cast safely.
I don't know your rod, but I have found that certain types of actions handle up lining better than others. This is a general statement for I know there will be exceptions, however I have found that rods which do most of their bending in the upper half, having relatively stiff butt sections, don't do well when up lined. Rods that bend progressively, in other words bend deeper and smoothly through the blank, the more they are loaded, tend to tolerate up lining much better.
So all that to say, if your rod has a noodle for an upper half and a stiff butt section, I'd stay away from the heavier line.
Field Staff G. Loomis / Shimano
Pro Staff Airflo, Simms, The Canadian Tube Fly Company