Q: I have a vintage Ford F-100 pickup with a transplanted 5.0L from a 1991 Mustang and the following mods: Ford Performance cam (220° duration/.498″ lift), Airflow Research CNC-ported 185 cylinder heads, Edelbrock Performer intake manifold, Holley 600 cfm carb, B&M flexplate with a 50 oz. balance, TCI C-4 Street Fighter transmission, and a TCI 10″ Street Fighter torque converter.
The water pump, pulleys, and damper are from a 1969 Ford 302. I am experiencing a sporadic vibration between 35-55 mph when driving and in neutral or park when the engine is revved. I can feel it in the gas pedal, steering wheel, and seat. The vibration goes away when I lift off the throttle. My mechanic claims to have sent the engine out to be balanced during assembly.
I believe something is out of balance or the torque converter is bad. Can you help?
A: We promise to try!
We think the problem is the balancer. In 1981, Ford changed from a 28 oz. to 50 oz. imbalance.
To fix the problem, simply use the original balancer from the 5.0L engine, or an equivalent replacement, and you should be good to go!
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I had the same problem when I put together my 65 Mustang. I dropped in a mid 80’s 302 in place of the original inline six. I used the factory 50 oz. balancer and the 28 oz C-4 flexplate not realizing at the time that they were not compatible. Talk about rattling the fillings out of your teeth. Stick with the factory balancer. B&M makes the flexplate for the C-4 that’s balanced to match the later model 50 oz 302 harmonic balancer.
62 F100 unibody 460 automatic same type of vibration could it be harmonic balancer or could it be torque converter? I have now heard my possibilities down thank you for the threads guys.