File this under it's all good.
What's your plan for the truck? If it's not destined to pull/haul heavy loads on long hauls with the air conditioning running stick with the 283. But if your looking for more power the 350 will certainly fit the bill on a budget. No substitute for cubic inches.
And if the 283 is numbers matching keep it like Bartamos suggested. Even if you just keep it in the corner of the garage.
Hope that helps..
