fireing order again

[marvink]

I am asking again to make sure to the fireing order on this motor,The rescue squad bought this motor and it had a burned valve in it so we went to get it fixed.Now this motor is in a big boat,they told us that the head was cracked beyond fix but they had a 302 head that would work.The broke head was a 351 winzor head,so we bought it and put it on.The motor runs great at a idle but when you shove the coal to it ,it backfires through the carb.I know that the fireing order is correct for the 302 but someone told me that that motor was a older one it was a 302HO MOTOR IN WHICH IT HAD A WINZOR CAM shaft,well the fireing order for a 302 will not work as I am told The Question I am asking is the fireing order for the 351 winzor going to work 13726548 any help on this we would thank you very much for we need this boat for water Rescue
Marvink