Just started a new build project on a 1954 GMC. 248 CID Inline 6 NOTE: Please don't provide opinions on the 248 engine vs swap. I don't want to swap it For some fun... seller told me the engine "would start right up" and the only thing keeping it from running was the wiring harness... Now that I know better I should have connected the battery and tried staring it using the starter "push ****on". Oh well... live and learn. After trying to start it no compression on most cylinders. Just had the machine shop break it down and found multiple bent pushrods. Two small cracks in the head, worn CAM and lifters, cracked radiator. Whew! looking for a CAM is the issue. All other parts seem easy to find. Cracked head was minor and repairable. Rebuild in progress. Cutting the head down 60/1000 and the block 20/1000. Looking for a street cam but not a big deal. Probably have the stock cam reground. Moving to a better intake with 2 barrel and better exhaust headers. That's it for engine mods. Expect about 8.9 compression ratio and around 170 lb/ft torque. Taking extra loads off the engine like fan and fuel pump. Should run nicely. Anyone have a camshaft or know what the part number is?
It can be tough finding new cams for some older engines. Not sure for your GMC. A regrind is always a possibility and a good cam grinder can put a little more duration and lift for slight performance boost if you want it. Seems your end result desired good street driver. So don't get crazy on too much cam.
Now i'm on the discovering just how uncomfortable the cab and seat is compared to my 2022 Silverado !!!