340 timing chain cover leak

I have had good experience with Superformance products.
As far as your timing cover leak, did you use sealant/RTV on the bolt threads before reusing them? Some of those bolts go into the water jacket and can/will seep or leak if they're not sealed. Also closely inspect the coolant passages in the timing cover, the aluminum can corrode to the point where it's leaking through the cover itself.