727 transmission or 340 trans

A manual Trans is good to about 600HP not 450. The week link on a 4 speed is 3rd gear. It will live over 600hp but you gotta baby the 2-3 shift. This is only if you are actually hooking the car that you need to worry about breaking it. Street car with 600hp don't matter cause you will not be hooking when you bang 3rd gear! On the race track different story.