I own a 76 c10, originally with a straight 6, 3 spd column shift, had a v8 350 when I got it, recently replaced with crate 350, and always felt like it needs another gear on fwy. I changed gauges and added a tach and on fwy it reads over 5000 rpm, so I heard should be like 3500 ? I don’t drive on fwy anymore, but need help with figuring out what gears I have and what to change them to ? Have 350 trans, and 17” rims tire size if needed, and do I wanna go post now ? Thanks