I have currently bought some bare 781 heads. Would it be worth it to replace the peanut port heads with the 781's. How much difference would there be. The motor is in a mud drag pickup. Nothing has been done to the motor except a new cam and some bearings. I don't think I would gain any compression. when I compared the chamber size I think both are 118cc. Also would it worth it to put bigger valves is these heads and maybe some port work if so how much would that cost. The motor right now runs really strong it would be hard to tare it apart for a few extra horsepower. Any advice is appreciated.