New gears = Messed up Speedometer

im not looking anything like that really, just the 4:10’s maybe a cam over the summer and all the bolt ons, 350 is outta my reach. But an 8.8 has definiatly crossed my mind once or twice, but right now i think its unneccesary. thanks everyone for the imput rmpoutlet.com sells a programmer plus underdrive pullies for like 400 and the programmer will fix the gear and speedo problem