I have been posting on another site about this engine work. to bring everyone here up to now! I have a 1950 gmc 3/4 ton with a 228 that has been bored out to 248 with standard dome pistons a year and ahalf ago the fiber timeing gear went and bent all the exhaust valves. So I had the motor rebuilt. The cylinders were in great shape so I had new rings installed the crank was ground and the head was completely rebuilt with new valves, guides and head resurfaced. put the engine back together and set valve lash and timing started it up ran great drove around town no problem took it oup to around 45 mpg and the rocker arm shaft broke. I replaced the shaft I thought that maybe it had been stressed or crack when the timing gear went Set vavle lash and it was runing agin tried to go to a car show and about 4 miles outside of town the rocker shaft broke again. I got it home and pulled the head and took it back to the machine shop to get it check out maybe the guides were to tight causing the shaft to break.
The machine shop called this morning and said he didn't find anything wrong the guides and valves were all fine. He did say he reground the valves because maybe the vavles were setting deeper in the head maybe causing a coil binde in the vavle spring. I am not sure if this is a stock cam so I am going to check this when I get the engine put back together. Is there anything else that maybe I should check before I start to put it back together?
