I am interested in having a new 489 third member built for my 65 Belvedere. I hear of Nodular casings and then different posi units. Each supplier has his own choice yet I personally are not sure what would be best for my car. Some help from my friends here would help broaden my purchase. I have been told the Sure grip,Auburn, then the Detriot TRU-trac. Cone-type then again the clutch-type gets tighter with the more power to it. Geez who can decide? All a sales pitch..

My application; 65 B body 500"stroker. 550+HP 727 with 3500 stall. Running 29" Hoosier QTP on street with Caltracs. Basically a strong street car. I do not mind an agressive unit on the street as I am not driving long distances. My choice is leaning towards 3.91 gear ratio.
Any help is well appreciated. Seems the price most guys are asking is around $1200-1400 with shipping.
Any other guys out there have anyone who builds to spec here?
Thanks .Bill.