I have a QT-54 as well. I bought mine when they were still made in the US. I put the same mag starter on mine as well and an hour meter also. I put a big 4" liquid filled gauge on mine. I ran some Rapidair 3/4" maxline in my shop to supply air where I need it. It's been a good compressor and runs fairly quiet.

Sir, I believe it's only a 2 cylinder pump.