340 and 360 heads have the large size exhaust ports. 273, 318, and magnums all have the smaller size exhaust ports. The "302" 318 heads have the small exhaust ports also.
318 "302" heads have the larger ports. I put a set on my '69 318 and the ports fit the 360 gaskets exactly. My Mopar book also states that the 302 heads come with the larger ports.
