Since the HotRod article specifically addresses the 727 transmission, I'm not sure their fluid recommendation would apply to the earlier 488 cast-iron TorqueFlite in my 1957 300. My transmission was rebuilt by 300 Club TorqueFlite Guru Don Verity, who
recommended Type F for that transmission, and I'm sure he was aware of the ATF+4 fluid when he rebuilt it a couple of years ago. There was also a thread regarding the thermal stability superiority of the new synthetic fluids, but raising the possible incompatibility
with old-formulation seals, leading to leakage, so I was reluctant to experiment! The Type F seems to be working OK now, although it puked at least a quart out the dipstick tube after driving only 20 miles (initial overfill?) but has settled down after that.
I barely have 200 miles on it yet.
Ray Melton Las Cruces, NM 1957 300C convertible s/n 3N572517
On 8/30/2017 6:08 AM, RICK AND DEBBIE CLAPHAM wrote: