The engine was built about 10 yrs ago, noy by me but a circle track engine builder. It has the 400 flex plate and balancer, I dont know the specs of the cam but its pretty lopey. It has 305 heads which the builder reworked the flow of heads and knews valves. As far as the idle in gear I have always had problem with this, tried different carbs,pv,jets,squirters. It is converted from points to hei found out yesterday the the old resister wire was powering the hei, changed that made a hugh diff but still wont idle good in gear. Have a single plane wiend intake,, just purchased a performer rpm, going to install when i recieve it in mail(purchased from ebay first time purchase on ebay hope everything works out ok) but my main concern is the vibration