66 325 hp 396 engine pics

[olredalert]

-----From 1965 thru 1966 there were small bosses cast into all big-block heads that were drilled and tapped for a quarter/twenty threaded bolt to hold on those shields. I am unaware of any big-block heads after these dates that had the bosses cast into them. Your 1969 Nova should not have had heads with those bosses. Check your casting #s as you most likely dont have the original heads. Im not sure weather the shields were used on low horse 396s in 66, but the bosses were there and tapped on them anyway.
-----There were some other plug shields that were used primarily on trucks that did not require the bosses. I believe they bolted right to one of the exhaust manifold bolts closest to the spark-plug. They looked quite a bit different but I see them mis-used frequently.......Bill S

[1969L78Nova]

Bill,
I have the original heads.
The shields installed on the Nova were fastened onto the exhaust manifold bolts as you described. Glad I removed them since I am now aware that they were not used on L-78s.
Martin