I have a '63 C10 that recently had its original 230 replaced with a 1965 292. The 292 was built as follows:
- bored .060 over, standard dished pistons
- crank polished
- Howard Cams 151021-10 cam with .502 lift
- head rebuilt with 12bolt.com 1.84/1.60 valve and lump port kits, stamped steel 1.75 rockers on 3/8" studs
- Langdon's cast iron exhaust headers with 2.25" dual exhaust
- Clifford ram flow intake with Edelbrock 1404 500cfm 4bbl
- eBay electronic distributor
The engine ran pretty well during and after a break-in period; idled smoothly with good throttle response. Recently while warming up in my yard I heard a huge miss develop and I quickly shut it down. What I discovered was the rear pushrod cover was bulging out and oil was running down the side. I pulled the cover and saw this.
That's the #4 intake lifter next to a broken pushrod.
I pulled the valve cover to find this.
Thats the #4 exhaust rocker broken. Here's a better picture.
My first thought was that something evil had happened to break the rocker and cause the rest of the symptoms but I pulled the head off and everything looks good. Now I am thinking that the rocker broke on its own and is the cause of all the other mayhem.
Should I be using different rocker arms on this build? The cam isn't too aggressive but it is a long step up from stock. I have looked at other similar 292 builds and stamped steel rockers seem to work okay. These rockers came out of an EngineTech overhaul kit so they aren't top shelf.
Thanks for your thought...ned.