I built a 12wt Sage RPLX for tarpon fishing. A fighting grip was placed about 4 inches abovet the front of the foregrip, but now I'm concerned that it was to far up and that if I tangle into a large fish, and use the fighting grip, the rod may break. Any have thoughts on fighting grip placement?

I've seen it happen. The best route would be something like was featured in the current issue of Rodmaker where an integral fighting grip is fashioned right at the top end of the casting grip. This gives you a bit more leverage but not so far up the rod that you'll run into problems.

Look also at the Sage factory rods and see if they have the fighting grip where your's is. If they do then they must be satisfied that it's not going to hurt anything on that one. If they don't, then there could be a reason why you shouldn't either.

I would'nt sweat the placement so much as how You play a tarpon.All the technical stuff aside, a twelve weight will handle any tarpon that swims, Mikes right, just get in the ballpark,if you tangle with a big "Poon" ,theres a thousand other things that'll go wrong before you break the rod.

Fighting grips are really a misnomer - - they should be called resting grips, because thats all thats accomplished by using them: you can rest your arm a little but you're actually putting LESS pressure on the fish. When the fulcrum point is moved to a smaller diameter part of the rod there is less power, not more. You can break a rod that way, I've seen it done, which is actually the only rod I have physically observed being broken by a fish. A very large Tarpon struck close to the boat and the angler was so surprised that he grabbed the rod at the fighting butt and reared back with all his might - - snapping (exploding) the 12 wt. immediately above the fighting grip. His technique was about as faulty as you could get but I don't think he could have broken that rod if he had stayed on the lower grip. I no longer put a fighting grip on any rods unless the customer absolutely insists. The type shown in lastest issue of RM looks to be the best I've seen.