[GNVYUS 1]

Coil packs are notorious for starting to miss as they get around 50k on these cars, it really comes down to how much boost and cylinder pressure you are running, worth swapping to see if it clears up.

Assuming you are .030??
Anything over .035 might enhance spark blow out on the top end, especially with an older coil pack.

Since your wideband is reading rich, it can be said that you are overworking your pump to keep up with your current fuel demands the injectors are calling for. Though your pressure is not really high at 65psi you are really working the Walbro with it pushing E85 ( less lubricity than gas ). I would consider dropping the fuel pressure ( less strain on pump at WOT ) and then make up for it in the injector if needed. And since you are running so fat already you probably will be ok with a basic pressure change.

It basically comes down to volume with E85 since it will need about 30% more up top. Keep your fuel pressure lower if possible and work the injector and you can probably push the one pump safely.

If you had a monster pump and lines then all bets are off, but the tiny Walbro pushing E85 through stock lines is going to fall off the chart at pressures of 60psi and beyond. It sum what does that already on gas and using the stock filter is probably going to come back to haunt you, a ton of talk about alky and paper elements all over E85 boards.

Just so you know, I have an E85 69 GTO so I am not giving too much internet regurgitation here. LOL