Did they put the integral head 250 in that far back? Had they even built it yet? (I don't think so, but it had a different bracket) if not and you have a "normal" 250; give me a few days and I'll measure the brackets I have and send you the drawings. Nothing in the local boneyard? 80's stepvans? Does your alternator bracket have the extra hole to the driver's side of the slot?