The fresh air tubing/hose should be the same size as the nipple on your Hydrovac...it could be 1/2" or 3/4".

My Illustrated Parts Book shows the 1962 trucks used 1/2" steel tubing (if needed I'll dig to confirm '58 is the same), but I think copper will be just fine.

Mike B smile


Mike Boteler

1956 Chevy 3100 Resto Rod
1952 Willys M38 Army Jeep
1983 Jeep CJ7 Laredo
1984 Jeep CJ7
+++++
Silver Spring, MD