A999 torque converter hub size

[RussellSullivan]

I have a late (1985?) 360 engine going in front of an A999 from a 1989 Fifth Avenue. The Fifth came with a 318.

I have read on here that the torque converter hub on 904/999 transmissions is smaller than 727s, and to my knowledge, Chrysler never used 904/999s behind 360s.

Is there a source for an adapter that will allow me to use the factory lockup 999 converter behind the 360? Changing to non lockup is out of the question right now, so I'm trying to work with what I've got. Thanks.

 

[Charrlie_S]

The hub size is the same. It is the 67 and older 904 hub size that is smaller. I am not positive, but I think you will run into an issue with converter balance, trying to use the 318 LU converter with the 360 engine. Someone else will chime in about that.

 

[RussellSullivan]

The hub size is the same. It is the 67 and older 904 hub size that is smaller. I am not positive, but I think you will run into an issue with converter balance, trying to use the 318 LU converter with the 360 engine. Someone else will chime in about that.

B&M makes a flexplate for that. It is balanced for 273/318/340 (internal). Thank you so much. I did not know it was a year change that made the difference.

 

[Charrlie_S]

B&M makes a flexplate for that. It is balanced for 273/318/340 (internal). Thank you so much. I did not know it was a year change that made the difference.

I know there are potential balance issues when swapping the later small block converters, but I just can't remember exactly what they are. I am aware of the ways to solve the problem. Glad I could help

 

[Locomotion]

To the OP - You'll need B&M 10239 to mate the 360 LA to the neutral balanced 318 converter. If you decide to go to a non-lock-up converter in the future, you'll have to change the transmission or get non-lock-up components installed in yours. But you can use the same B&M fleplate.

 

[lemondana]

Chrysler started using 999's behind the 360 2 barrel engine in 74. In 78 the lockup came out but not all 78's were lockup. Then after that the 999 was used in a hit and miss situation. The Diplomat and Fury cop cars used the 727's early and then switched to 999's. They used the 999 in some light duty pickups and full size vans.

 

[lemondana]

All of the Fifth Avenue 318 transmissions I have seen have been 904's. Check that PK number on the pan rail to verify what you have.

 

[RussellSullivan]

To the OP - You'll need B&M 10239 to mate the 360 LA to the neutral balanced 318 converter. If you decide to go to a non-lock-up converter in the future, you'll have to change the transmission or get non-lock-up components installed in yours. But you can use the same B&M fleplate.

I will be staying with lockup for now. Seeing as how nobody has an off-the-shelf performance lockup converter, I will eventually have one made. I dont plan on abusing the car, so the lockup should hold up for daily or almost daily use. Thanks.