transmission slipping, not engaging

[supersix69cuda]

i have a 69 super six 225 with a four speed auto
last week after driving for about 8 minutes the trans started racing
in 3rd gear rpms would go up to 3000 at 30-35 mph
later at a full stop light turned green and i pushed on the accelerator, engine reved in drive, and a second time, but the third time it reved it slowly engaged a started to drive forward real slowly
couldnt push it over forty and rpms were 3000 at 30 mph in drive?
any ideas?
its not the kickdown cable

 

[oldkimmer]

................69s dont have a 4 sp-eed auto, or a kd cable............it could b very low on fluid, but even if it is it needs a rebuild...........kim.....

 

[supersix69cuda]

its actually a 76 225 and it does have a kd cable and four speed, hoser

 

[fishy68]

its actually a 76 225 and it does have a kd cable and four speed, hoser

There was no 4 spd auto until the late 80's and that's not a good way to respond on a board when someone is trying to help you.:bootysha: