Transmission selection - First Generation Pontiac Firebird (1967 - 1969) - Firebird Nation

Jump to content


FirebirdNation.com is the premier Pontiac Firebird forum on the internet. Supporting Members do not see the above ads.
Photo
- - - - -

Transmission selection


  • Please log in to reply
4 replies to this topic

#1 scorpeon

scorpeon

    Firebird Newbie

  • New Member
  • Pip
  • 4 posts
  • Gender:Male
  • First Name:Martin
  • City:Calgary
  • State or Province:AB
  • Country:Canada
  • Interests:Working on cars is my passion
  • Year: 1968
  • Make: Pontiac
  • Model: Firebird
  • Engine: 350
  • Transmission: 2sp powerglide

Posted A week ago

I have a 68 Firebird with the two speed powerglide transmission I need to know if I drop the transmission with a TH 350 bolt right up

#2 ponyakr

ponyakr

    Firebird Master Tech.

  • Full Member
  • PipPipPipPipPipPipPip
  • 4236 posts
  • Gender:Male
  • First Name:don
  • City:jonesboro
  • State or Province:LA
  • Country:USA
  • Interests:bracket racing, cajun & zydeco music
  • Year: 1968
  • Make: pontiac
  • Model: firebird
  • Engine: 400,455
  • Transmission: th400, 4-spd muncie

Posted A week ago

I have a 68 Firebird with the two speed powerglide transmission I need to know if I drop the transmission with a TH 350 bolt right up

 

First you need to verify exactly what trans & engine you have. Is the 350 engine a Pontiac, Chevy, Olds, or Buick ? 

 

Is the trans REALLY a Powerglide ? Or is it actually a 2-speed BOP trans, commonly called a Super Turbine 300 (ST-300) ? 

 

A BOP engine requires a BOP TH350. A Chevy engine has a different bolt pattern, requiring a trans with a Chevy bolt pattern. 

 

BUT, there are conversion plates which allows mating Chevy trans to BOP engine, & BOP trans to Chevy engine. I made one out of 1/8" plate. The bottom & dowel pin holes are in the same locations, for Chevy & BOP. 

 

Don't know about driveshaft length. I've never switched from ST-300 to TH350. Some of these guys who have made the switched can tell you.  . 



#3 scorpeon

scorpeon

    Firebird Newbie

  • New Member
  • Pip
  • 4 posts
  • Gender:Male
  • First Name:Martin
  • City:Calgary
  • State or Province:AB
  • Country:Canada
  • Interests:Working on cars is my passion
  • Year: 1968
  • Make: Pontiac
  • Model: Firebird
  • Engine: 350
  • Transmission: 2sp powerglide

Posted A week ago

I have a 350 Pontiac...Not sure about the (BOP)Transmission
Are there distinguishing marks on the transmission or just buy the serial number

#4 Martin Cooper

Martin Cooper

    Firebird Newbie

  • Full Member
  • Pip
  • 38 posts
  • Gender:Male
  • First Name:Martin
  • City:Estero
  • State or Province:FL
  • Country:USA
  • Interests:All things Pontiac
  • Year: 1967
  • Make: Pontiac
  • Model: Firebird
  • Engine: 326
  • Transmission: Auto

Posted A week ago

If your car is equipped with the original engine and transmission then you have the BOP 2 speed ST300 transmission. This transmission is frequently referred to as a Powerglide which was the Chevy 2 speed automatic. They are completely different transmissions. A BOP TH350 will bolt in where an ST300 had been, including the driveshaft and crossmember without modification, but the TH350 will require different means for controlling downshifts.

#5 scorpeon

scorpeon

    Firebird Newbie

  • New Member
  • Pip
  • 4 posts
  • Gender:Male
  • First Name:Martin
  • City:Calgary
  • State or Province:AB
  • Country:Canada
  • Interests:Working on cars is my passion
  • Year: 1968
  • Make: Pontiac
  • Model: Firebird
  • Engine: 350
  • Transmission: 2sp powerglide

Posted A week ago

Ok thanks




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users