[Your41Plague12]

If it sputters under load, check the advance weights in the distributor. Take off the cap and there's little blade-like weights inside. Sometimes they seize up or even rust together if the truck (or just the distributor) sat for a while. If you have the cash, a new distributor can never hurt. If not, just use some kind of penetrating oil or lubricant and make sure they move freely. The exact same thing happened to me and this solved my problem instantly.