273/ 2 barrel camshaft options

Bottom line is, if you want to order an off the shelf solid lifter cam for your mild 273, the E 4 will work fine. If you want something smaller, you will need to have one custom made. No real issue, just another step to take. Will your engine know the difference? Probably not enough to notice. I advanced mine a few degrees and it has good power throughout the range. It is topped out at about 5,000 but there's no need to twist it any higher.