For a sort of gift, my mom bought me a cam kit from postons. The cam is a 110t and the duration is 266/258 is this a good cam, the right cam for an 81, or can I use it if I bought an 87gn? It came with their PE4667129 taht rev to 7500, P815214 heavy duty 5/16" chrome moly pushrods, P4993468 high performance valve springs (dont know the seating pressure), and a cambutton/spring. Also does anybody know what the cost of an 82 or 83 0.63 A/R housing is and where can I get one? Thanks.