I have never heard any complaints from using new ones , but I never looked for any comments about the subject. I put new axles from Zip corvette in my 77 , they came with studs already on them , never really took much notice of them after and never had a problem and that's been down the drag strip a few times as well. No big burn outs or such ,but as hard a take off as you can get without spinning the normal type tyres. Just a bit of fun .
I think the Moroso ones are a good quality , I've got the 1/2 inch ones for another project .
As for a pipe , yeah I was lucky enough to find some steam pipe that has the right internal dia. I had to get the external turned down a bit . (which reminds me I lent it to someone , thanks for the reminder