Big dilemma there, as the GMC stuff just will not fit on the Chevy stuff,,,,UNLESS it is Canadian built. I see that Kanter vintage auto parts has a deluxe rebuild kit for a 228 GMC for $850(includes new valves and guides for the head)
There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us. - - Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!