I'm trying to remove the exhaust manifold bolts on my '67 firebird (Pontiac 400) engine. The problem is, none of my sockets or wrenches seem to fit. I've tried 6 side sockets, 12 side sockets, wrenches, etc. and every 9/16" is too big, every 1/2" is too small.. I've even tried metric.
The bolt heads I tried are fine, not rounded over, and are not obstructed by anything, either (none of those pinched metal brackets, etc)
Is there a certain brand tool you can recommend, or any other tip/ tricks would be appreciated.
