I have a 1952 M135, while coming home from a event, we were on the highway an traveling about 45 MPH. All of a sudden it was like we lost power and could bearly get 30MPH. We got it home and figures we had a clogged fuel filter. We have 2 fuel filters on it one is an inline clear type with paper filter in it and after that we have another micro filter in it. Both filter were changed, no change in the power loss. Then we thought maybe the fuel pump was going bad and we had an extra so we changed that, no change in power loss. Truck idles smooth and starts right up. Anybody got any ideas what it could be?