With the temp getting above freezing i decided to re-bed my intake manifold today, i had a very small leak at the back near the dizzy on the china wall, this may have partly been due to the higher crank case compression of the 383 or bad install by me, i installed a crank breather from the blanking plate on the mech fuel pump hole a few weeks ago to relieve some pressure.
After stripping off the manifold i had a careful look over the intake gasket which seemed to be fine, i wanted to check for potential vac leaks in that area.
The RTV i used to seal the front and rear china walls all came off with the manifold, looking at the block there was no real sign of any leaks altho the RTV looked like it hadnt sealed the full width of the rear.
I was suprised not to find a leak there and was beginning to wonder if i had stripped of the manifold prematurely, altho a leak was present when the engine was under load.
Using a razor blade almost horizontal to the manifold i carefully pealed back the RTV then i found a small section about 15mm in length that came away with no effort, found it! releived that i wasnt going mad and there was a leak i cleaned up the block and manifold and fitted new gaskets and laid a thicker bead of RTV this time.
The remains of the sealant took over an hour to remove using a razor blade and thinners to remove the last traces.
Before i started i placed rags in the block to prevent any debris from getting into the lower block and valves.
The china walls were cleaned down, i used 240grit wet and dry to key the block then cleaned down with thinners to remove any trace of contaminates.
Manifold bolted back on at 25ft/lbs in stages as per the install guide.
Why the top end is off i will check the carb and replace the valve cover gaskets with the steel reinforced rubber ones.