I have a 78 Dodge B200 van, 318, 4 bbl, with 352,000 miles on it. The engine was rebuilt at 155K and seems to be running solid. Timing chain was done about 20,000 miles ago. I've always run Castrol 20/50 with changes, including Napa Gold filter, every 3k. I just switched to Castrol "high milage" 20/50 this last oil change. (100mi ago)
My friend who works as a mechanic and has lots of years under his belt does what work I need, as I need it. This last time he said he heard a tapping under the valve cover on the driver's side. He figured rocker arm and push rod (probably just one). Since he does the work for me after hours in the shop, I have always done the part locating.
My questions are these, does anyone make an adjustable pushrod for my application? Is it okay to replace just the "bad" rocker and pushrod? Which valve cover gasket has the best leak resistance over time, rubber or cork? Are there any special pitfalls to watch for in doing this repair? What if I just leave it alone, what can happen? Is there a SAFE way to clean crud from the lifters, if that is all that might be causing the problem?
Thanks for whatever help you can offer!
-cadjak