Hope this can help. Since you stated that you tried everything as far as carburetion goes here is a few things to check out on that stubborn miss.Not in any certain order. 1. Check for leaking intake manifold gaskets,you can see them pushed out visually. 2.Have a tech put a test on the SAM(SPARK ADVANCE MODULE)this will cause ignition problems which will make the engine act as if a coil is bad. 3.Take your plug gap to .025 4.Pop the valve covers just to make sure all is well Hope this helps!