I have read some of these posts. a 340 4bbl trans has a lighter govenor weight so it holds second longer. I have also seen many 4bbl car and guys heve the correct linkage but the wrong lever on the trans, This always happened at trans shops when a trans was replaced . Yes when it went in for a repair at sometime in its life it got a 2 bbl trans, The govenor weight which is in the tail shaft housing would be lost as well as the 4 bbl lever on the trans. I remember drilling levers at cottman to install rebuilts off the shelf so they would work with the lower push arm. The lever on a 4bbl car is aleast a 1/2 inch shorter then a 2bbl. Another thing to do is add a part throttle kick down servo to the valve body from a six or a fleet car or 4wd truck, 904 an 727 are the same, Three screws on the side of the valve body. The biggest improvement you will make. You will not have to floor it for a down shift. It will even go into low by itself on a slight pull.If you hold a steady throttle and it shifts as soon as you apply more throttle it will down shift if it needs on its own. The factory did not put these on performance cars because of loosing traction in the wet. I am going to list correct 4bbl linkage for a 340 today I will also picture the wieght and the servo if I have one out. Check for my listing, I have two ready I will sell one. I keep one to put more together out of the linkage box.I saw this was an old thread but never saw this mentioned. And I hear alot of guys wiyj the same problem today.
