Direct swap. Plug-n-Play.
Without modding the arms, the biggest blade I've found that works is a 19". Factory size is 18". The 19's just come up to the top of the glass without hitting the body.
I've run that size for years & they don't skip.
But, West Coast RainForest here. I go through 2-3 sets of blades a year. Everytime I change the blades, I'll go over the glass with some windex & #0000 steel wool.
Pull the cowl cover & grease up the transmission.
Make sure nuts & bolts are tight.
I carry a new circuit board in the glove-box.
Overkill? Maybe. Probably. But...
Annual rainfall = 50.5"/yr. Fifty-freakin' inches!
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