Most people go with an aluminum unit, or when they are doing a swap it's a 1 for one exchange. If I remember the IRS driveshaft is slightly shorter than the solid axle one, however you can still run it. Why not just get a FRPP "J" driveshaft and call it a day? If it's a money issue, wait until you have the cash to buy one and then do a swap. But to answer your question Yes you can run a IRS driveshaft with a solid axle.