Re: Penn 704z
704 refers to greenie(older model) 704z refers to blackie( newer model) same reel though. Parts are interchangeable on the 704(z) and 706(z) because they share the same housing thus the guts are all the same size. The 710 being a smaller housing should have a smaller main gear than the 704(706). Better yet, the 704 main gear shaft is 8mm (outer diameter). Measure the shaft on the 710 and if it's 8mm it might work. What's wrong with the original handle?