firing order 1982 351w
jpourner is correct. Try the other firing order if you want to.
Or if you want just measure the width of the intake on your engine and compare it to a car/truck that you know has a 302 in it. If yours measures the same then you have a 302 or 289 (the 289 has the 302 firing order). If yours measures about 3/4 inch wider then you have a 351w.