I have an 81 Custom Deluxe C10 that was originally a 6-cylinder model and it has 15x7 rally style wheels (I think - hard to measure with tires!); the previous owner mentioned that he thought the 15x7 were the stock wheel for a 6-cylinder model, is this correct? And so in 1981 did any V8 models have 15x7 wheels or did they all use 15x8? Thanks for any info.