GMC 348? More likely a 248. I'll measure the plug in the back of my 302 head later tonight and verify that the 228-235-248-256-270-302 GMC heads all use the same plugs. Gotta go now.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
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