Im Thinking of chooing between 2 Distributors: MSD standard billet part#85551 and MSD extra duty ready to run part#8360. The 454 has an hei with vacuum advance right now, so im thinking that the MSD#8360 would be a good choice since it comes with vacuum advance too? The motor is stock right now and soon I will be putting an edelbrock intake,carb, headers, cam,etc...but for right now witch distributor would fit my application? Thanks for any replies.