So, it's no longer "bucking like a bronco" ?

If it has the wrong governor it might shift too early ....but a wrong governor won't cause an engine performance problem. If you have one...which I'm getting confused about!

Cheers
DD

 

no yeah it shifts too early. The engine performance feels good to me. This is the only jag v12 I've driven so I wouldn't know if it's lacking power or not but feels like great tq to me. I guess that's my main question... if you try to hold a gear with a lower governor will it not allow it to hold the gear and still want to shift at the lower rpm? Cause clearly the car/trans wants to and does shift like 4,500 rpm

 

The 400 will make the 1-2 shift *even if you manually select and hold first gear*. If the governor is calibrated to 4500, that's when the shift will happen.

Some 'shift kits' defeat this operating feature so that the trans will stay in the manually-selected lower gear until you move the gearshift ....or the engine blows

Cheers
DD

 

ahh ok, thank you. Well I'm getting the feeling the trans and governor are off something else and it's not quite calibrated for the jag. In reality 4500 and this engine still makes for trainlike smoothness but I want to hear the v12 at 6k!

 

My 1992 Vanden Plas V12 shifted at 5000 in stock form. The converter is big on the GM transmission, I'm not sure that it can take high revs.

 

If having a 400 rebuilt for use behind a V12 (or other high output/high rpm engine) it is essential to use the correct spec torque converter. A plain-vanilla unit meant for grandfather's old Buick Electra won't fill the bill!

Cheer
DD

 

As far as I know the TC and the governor where what was put in at Browns Lane and it shifted at 5000 under WOT.