Complete rebuild. Top end and bottom end. Normally these engines were pretty much cooked at 100,000. Miles Hope this helps.

If the engine runs, check compression, pull valve covers to check carbon build-up. If engine is decent, run with it stock. they were good engines. As kids, we would have it bored to 283 specs. No larger. Cam it out, 4 bbl. or trips. What are you putting the engine in? 55, 56, and early 57 Chevies These engine with proper balancing and optional racing parts were very high winding engines because of there short stroke.