I'm going to check out a couple of complete drum brake 9" Ford rear ends I found for sale locally. One will be used in my '33 Ford pu 425 Nailhead powered and the other may go into my '49 Austin gasser, blown 355 sbc powered. Both will have to be narrowed to fit my applications. I will narrow the housings and the axles will come from Moser or MW. My question is; one rear is from an '83 F100 and the other is from a '79 F100, one 28 spline the other 31 spline. I'm no 9" rear end expert and I know there were lots of variations available. Any reason NOT to use these for my hot rods???? Thanks.