For the 6# lower only with stock upper, use a Gates k080790 (79"). Goodyear, unfortunatly goes from 78" to 79.7" Do you plan on using the 3.5 Alt. pulley? If so, the same 79" belt will work but it's a tight squeeze.
This is just a thought, but if you are planning on purchasing one of the upper idler bracket assemblies in the future, you might want to get it before buying the belt. The upper pulley requires an increase of about 1/2" in belt length(I think). This way you might save the cost of getting another belt later.
Thanks Harry. How long have you been running the 6# lower?
I left a message with Metco earlier today and Roger called me back from his cell on his way to FL(nice service), he suggested the 3.5 Atl pulley with the 6# lower and the 3.2 Alt pulley with the 4# lower.
The 6 lb. lower is a new addition to my car.....now I am just waiting for some mod work on the stock pulley cage so I can swap lower pulleys for different tunes. JDM has been a big help with that. I have the 2,4 and 6 lb. lower pulleys now.