Dynoed my cheap 383

Did you end up with new valve seats to go from the 1.60 to the 1.74 valve..?? I have a pretty comprable build in a 71 swinger 3.91, 4 speed car. Still has 1.60 valves, just curious what the difference might be….Thanks Swingn’
I cut the seats for the bigger valves using a Serdi. Then did a little porting.