First your gearing don't compare to others in your class, ask some of the front runners in the Sr 350 lb or 360 lb class what there gearing is and you should be same front driver with 1 less on rear, which provided you have a good blue plate motor will put you around 6550 rpm which is what you want for a oval momentum track never out of the throttle drops are 500 and under, then on tracks with longer straight's higher drops turn it 6700 rpm, If you find yourself chasing rpm then it's simple your set up, or tires are off or both, or your driver is not maximizing momentum same as the others are, I've been helping tune blue plates along with Sr now for many years and cream of the crop blue plates will turn sometimes same lap times as SR or with in a tenth or two, maybe 3 th unless the two classes are real far apart in the racing order because of track changing, YES your at a disadvantage being 40 lb heavy HOWEVER as far off as you are tells me you got other issues going on, you have to sort out what they are, as mentioned above could be set up, could be tires, could be the driver himself, could be a combination of those, without fixing those issues even if your class weight were 360 lb you'd find yourself at the back of the pack. As far as options based on the weight alone you only have one move up into Sr Class closest to your weight of say 360 lb.
Hope this helps !!