The rocker geo is going to be fairly straight-forward as both the pushrods and valves are parallel.
I've seen several references to GMC and 235 intake rockers interchanging (despite the stem angles differing: zero for the GMC and -3°26’ for the Chevrolet) but it suggests that the working lengths (stem tip to pushrod) are very close: about 3.41" (the Chevrolet exhaust rockers' angle is way off). The GMC appear to be skewed left and right as well (as are the Chevrolet at 8 degrees), but how close? IDK.
Using a high ratio offers an advantage in that a smaller lobe can be used and still clear the tightest cam bearing.
You may need a dual pattern cam favoring either side depending on how well the ports flow. Based on the 1-3/4" exhaust valves, the intake lobe may need more duration.
