That's almost NEVER the cause in my experience, and I do this every day. In my experience 99.9% of the time, its incorrect machining on the lifter face. I have the equipment to remachine lifters in my shop, and I will not install ANY lifter that I dont remachine first. In the past year alone I...
They probably wont be offset boring it once they find the factory bore locations are slightly off from blueprint anyway. The only way moving the bore is practical is to start with a block rough bored well below your finished dimension. Like a race block. Not a used oem block. Even then, the...
The only experience I have had with BB speedmaster stuff has been the victor knockoffs that use offset rockers. Those are a disaster. I've never used there conventional BB rockers on anything.
Another thing of concern, the pictures from underneath dont show the torque box areas. Could be lazy picture taking or could be purposely cropped out. Who knows. There are a few other things to verify, to confirm its legit. Buyer beware! It appears to be someone's unfinished project, with "barn...
I think its extremely obvious it's been painted underhood, and underneath, zero question about that. One thing I wondered about, is this area of the pass side inner fender. Was this a 72' up thing? I dont remember seeing that on earlier cars. Probably for the charcoal canister mounting.
The real issue is those blocks are over 50 years old now, and corrosion inside the water jackets eat away material over time. A sonic check is a great idea, but one small pinhole is easily overlooked even in a sonic test.