I have a set of stock '58 vette wheels less valve stems. I plan on installing full wheelcovers and would like to confirm the required length stem. I recall seeing 1 1/2" the right length (measured from external wheel surface to very last cap thread) but that looks short, though I haven't acquired the wheel covers so I don't have anything compare. Don't want to mount my WW's and then have to take them off...although that wouldn't be the first time I've backup. Thanks