BlackStealth- My Company makes the Coolingworks Chevette Shroud. Unfortunately, you got oddball core. The shroud size is listed so that you can make sure the shroud will fit the core you have before you buy it. I’d recommend you return your core to the auto parts store and ask the auto parts guy if you can measure a few different Chevette cores and exchange it for one that is the standard size- 6 1/8 x 6 1/8.
email me at
info@coolinworks.com if you need some help or have any questions.