I have adjusted the timing , seems better now . I also leaned out the fuel mixture . Wife drove it before that and it was missing under hard (her normal) acceleration . I did just look at the vacuum advance as I had to replace it on the 54 . Iv'e got an hei unit sitting in a box for this motor , better get to it.
Thanks

First time I saw this truck I said "That's the one!"
1954 Canadian-built Chev Short Box