I recently swapped a '56 235 into my '53 GMC 100. There were a few issues to sort out, including a carb rebuild. I took care of that and now it's overheating and running at a faster idle. I'm thinking its running lean AND has crud in the cooling passages because it didn't heat before the crab was touched (Rochester) and NOTHING comes out of the rear block drain plug (driver side). Thing is, it starts up pretty well cold, which makes me second guess the lean condition. I put in a bottle of rad flush today and messed with the timing a bit. Any other tips/ideas???
