If you are wanting an overlay then really the only accurate way is to trace the emblem, scan it in, test fit and then make adjustments as necessary. This is tedious and time consuming but if you want it done right it is the only way. Even if you find someone selling "templates" 90% of the time they aren't accurate enough to trust. And you can probably find that logo online but who knows if the proportions will be 100% accurate even if you get them to be the perfect size. This is the type of product that if I wanted it for my own truck I would just buy from another company...not worth my time an energy to do all the work to save a few bucks.
