Did you have air cleaners on it?You have to have a flat hood with the carbs popping up thru and put the air cleaners on it..you will have to much turbulance without the air cleaners..

Think about it..you have a big motor with big carbs and a big intake..needs alot of air to get it moving..

It probably goes 600 feet and quits pulling..been there done that...cowl hood take alot of R/D to get to work...