| FAQ |
| Members List |
| Social Groups |
| Calendar |
| Search |
| Today's Posts |
|
#1
06-23-2026, 09:51 AM
|
||||
|
||||
AC add-on 1-groove pulley - which direction does it mount?
Replacing my front main seal and balancer... didn't pay attention to the pulley mounting when I took the crank and AC add-on pulley.
Does anybody w/ a 400 and AC remember what direction or can check their AC pulley? Because both sides aren't exactly alike. I want to say that the side with the convex raised center go against the balancer, while the side with the concave center faces the back of the crank pulley, but I don't know for sure. I know that it wouldn't be that big a deal to just bolt it down one way and check to see if the AC belt is aligned like it was before, but I'm just seeing if anybody knows off the top of their head. Pic for reference: Concave center:  Convex center: 
__________________
1979 Trans Am W72 400/4-Speed WS6 - Starlight Black Hardtop  |
|
#2
06-23-2026, 03:35 PM
|
||||
|
||||
|
Yea I always have to look at it 10 times! Then I hope the paint is scuffed from the balancer side! I'll look tonight I have 2 in the garage.
__________________
Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune [email protected] 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs 1964 Corvette Coupe 327 4 speed |
|
#3
06-24-2026, 02:18 PM
|
||||
|
||||
|
Stack the two pulleys together (not on the balancer). One way will have a gap between the flanges and the other way not.
|
|
#4
06-24-2026, 03:29 PM
|
||||
|
||||
|
Quote:
The side with the convex center also has the belt groove lip a little higher than the concave side.
__________________
1979 Trans Am W72 400/4-Speed WS6 - Starlight Black Hardtop |
|
#5
07-04-2026, 04:14 PM
|
||||
|
||||
|
Yes mine look like the bottom picture.
__________________
Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune [email protected] 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs 1964 Corvette Coupe 327 4 speed |
| Reply |
|
|
The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.
Linear Mode
