Well...."we" installed the Langdon's HEI after two years frought with other problems on "our" truck. Bumped the startrer and it roared to life.....very cool...put smiles on both of our faces!! We are still fooling with the timming right now we are at 550- 650 rpm vacuum at 18.5 and the ball on the fly wheel( with timming light) about 5/8 of an inch to the left of the pointer. Since we are both hard of hearing we think there might be just a little pinging with foot into it on a very long steep hill??? Do these numbers seem right? The thing goes like a bat out of the bad place...(GOD Bless Mr. Langdon) MAN what a difference....OK let me know what "we" should do next on the timming and t/c Steve