I have had very mixed results with resin cast parts and bodies. In to many cases its just more trouble than its worth, What I did do on a resent build that I wanted a cowl hood for was use the hood from the '69 Nova SS. I cut the cowl portion of the hood and cut out the center of the hood for a '66 Impala build. The hoods are the same thickness which helped and only used minimal filler. I would suggest you try making your own, and if it turns out the way you want then cast it your self for the future.