Need a Buick Nailhead Expert! ASAP

Hi, I just replaced the 1963 buick nailhead 401 in my 1936 international. I have a 1965 buick nailhead 425 and just got a st 400 ******. Is there anything I should know about that ****** before I bolt it to my motor. Is there issues with timing? Or is there anything I should look out for. I have never used one of these transmissions before and I heard there was something about a variable pitch in it? Please let me know what you think. Thanks!

 

nothing magic, it's a TH400, a ST400 does not have swtich pitch, a SP400 does.

 

Only some had the variable picth torque converters, i think they stopped that in 64 not for sure. easy to check, there should be a one wire lead on the drivers side bell housing area.

 

Yes I think that the th 400 and st 400 are the same. Ok, that is what I was confused about when I heard about a switch pitch transmission. Thank you!

 

the switch pitch, not to be confused with the Dynaflows variable pitch, started in '64

 

In 1964 buick nailheads switched to the st400 or the th400 for 1964-1966. They stopped using the dynaflow. Is this correct?

 

Here ya go, the tune up sheet for the 65 425..

 

yep, though a few select GS models got ST300's (2 speeds)

 

64's used ST400 (single range) no variable pitch. 65-67's used SP400 variable pitch (dual range) transmissions.

 

You keep saying this. But all the 65-66 were not switch pitch. Fact!