I think that the first gen Holset turbo should be fine, because I heard they push around 15psi stock. 15psi max for a stock 5.9 liter engine should net you a something like 12psi max for a 6.9/7.3 liter engine, but that is just basic thinking that is probably wrong. You need to be albe to do a lot of fab work if you are actually going to do this.