[BigRed250]

so I am looking for a little more trail grunt as most of my riding is on single track, usually deep sand (Michigan) and could use a little more torque and tire spin at times. I currently have the 13/42 set up. Wishing to go to the 13/45 or even the 13/48. I know I will need a new (longer) chain, but what are my options for the rear chain guide? I've read somewhere about flipping the chain block upside down??? Wouldn't it be better to get a new rear chain guide that is made to accommodate the larger rear sprocket all together? If so who has recommendations/part #'s for a chain guide that could be used with the 13/45 or 13/48 set up? And will I notice enough difference from a 13/42 to a 13/45 or should I go straight to the 13/48? I do road riding on occasion, but 50-60mph is all I need to go, so not sure how much I'd be sacrificing top end going to the 13/48??? Thoughts/suggestions? TIA