I would say that it's dependent on your tolerance. Poor compression, leaky rings, burning oil means less power. You can drive the thing until it can't go up a steep hill. Or you can run one quarter mile and tear it down. Most people fit somewhere in between.
You can run it with a knock or a tick, or not. Are you cruising, or racing?
Probably if you talk about specifically what your goals are and what symptoms you're experiencing the experts here can help you.
Engine is a '67 289 w/109,000 mi. Still runs strong. Doesn't burn oil. I am noticing ticking while it warms up... seems to get quieter when fully warmed. Car will be for mainly street use, maybe a trip to the strip once a year. Would like to end up with 300-350 hp when I'm done.
Engine is a '67 289 w/109,000 mi. Still runs strong. Doesn't burn oil. I am noticing ticking while it warms up... seems to get quieter when fully warmed. Car will be for mainly street use, maybe a trip to the strip once a year. Would like to end up with 300-350 hp when I'm done.
It could be a lifter (hydraulic), maybe a rocker arm loose, rod bearing? I had a 289 once a long time ago that ran really strong, right up to the point when the piston ended up sideways in the cylinder. If you're after 300 hp and want reliability, I'd start from the ground up, but that's just me.