The chain set needed depends on the vehicle it is going in...not the block you are running. An 09 G8 is definitely 58X on the crank and 4X on the cam gear. With the 2X gear, it would have a hard start about 50% of the time, because that's basically all the cam gear reading is used for (to determine which cycle the engine is in, where in the firing order it is). It'll start better and easier with the correct gear for sure, and if you had any tach issues with that other set, that'd be fixed too.
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