Topic: Questions about Belt and Pulley System for 67 GT 390 w/AC PS and Thermactor

[JIMeast]

Did the 390 GT with thermactor, AC, PS have two idlers in the belt and pulley system?  My car only has one, seen in this product picture ;

http://www2.cougarpartscatalog.com/c7sz-8678-b.html

I'm not sure if there are other correct variations of the pulley system with these options that would not use a 2nd idler. 

Edit: I found this on the web showing 428 CJ belt routings, http://www.428cobrajet.org/id-belts  Can I assume my routing is the same, with appropriate parts and part numbers for a 67 390 GT?

[J_Speegle]

Suggest you invest in at least the drivetrain version of the 67 Assembly manual - lots of pulley and belt drawings. Not always exactly like what was done but the vast majority is, just check the page date and compare to real cars from that period

To your question - Yes your car would most likely (according to Ford documents) have had one idler between the AC pump and the Thermactor pump and a second between the crank pulley and the AC pump

[Bob Gaines]

Did the 390 GT with thermactor, AC, PS have two idlers in the belt and pulley system?  My car only has one, seen in this product picture ;

http://www2.cougarpartscatalog.com/c7sz-8678-b.html

I'm not sure if there are other correct variations of the pulley system with these options that would not use a 2nd idler. 

Edit: I found this on the web showing 428 CJ belt routings, http://www.428cobrajet.org/id-belts  Can I assume my routing is the same, with appropriate parts and part numbers for a 67 390 GT?

The 390 A/C used a upper adjustable idler pulley and a adjustable  lower. These two idler pulleys are completely different in appearance then the later 68-70 set up. The upper steel compressor bracket is different from the later 68-70 style as well. The changeover occured in early 68 production.