I Have A 1940 Ford Pickup With A New 350/350 Combo,8 Inch Rearend, On A 1983 Ranger Frame.runs Real Sweet, But Here Is My Problum.i Have Checked My Angles Time And Time Again, I Was Told 3 Dagrees In The Front End Rear That Is What I Have.the Part That Drives Me Wild Is The Vibration Only Happens When The Truck Is At 50 Mph And Has Been Drove For 3 To 5 Miles It Dosnt Happen Till It Seems Like The Truck Is Warmed Up If Anyone Has Clue Let Me Know. Its Driveing Me Nuts!!!!!!!!!!!!!!!!!
I know you may be smarter than i but its a possibility, Have u checked if the parking break is on? I kno who could be that dumb. I am. I was leaving a friends house and the car started violently shaking around 45 mph n i had no idea what was wrong untill i got to my other friends house and relized i forgot to take off the parking break. Stupid stupid me.
How are your engine mounts, prop shaft, shocks, ball joints, strut brace, rear leafs, etc.
when it's vibrating, put it in neutral and let off the gas. could be it's a slight miss that's not evident until you have a constant light load on it...