97 Deville miss on #7 and somtimes 3

[lucas_wojo]

I just got done doing an engine swap on my 97 deville. The engine came out of a 98 Deville and was purchased from a junkyard with the tranny attached with a warranty that it is all good.. The engine installed great for my first northstar swap and I will do it again for sure. However, I replaced the intake gasket, oil pan gaket, rear main seal and valve cover gaskets and plugs while I was there. The car started rite up but it has a miss on #7 and a low count mis on number 3. I took the plug out and it was wet with raw fuel, I cleaned it off and swapped it with #8 and changed the wire. I also swithced a coil pack around to see if it changed the miss location but it did not. The miss seems worse at an idol but when it is under a heavy load the count levels off untill the preasure is off the throttle. The converter was stolen off the car prior to my purchase so it is also reading open o2 sensors but that I expect. The car does not backfire and has plenty or power. I have not done a compression test yet. I have also checked the vaccum lines and all is well. I did notice that the octane was 87 when I had the scan tool hooked up but it runs smooth for the most part and it has 14 gallons in it. If the car idols for a minute or two you can smell raw gas a little. What should I check next? Any quick fixes or this is how to fix it answers? I have a 97 Aurora so I am framiliar with the northstars a little. Thanks for your help.

The old engine had a bad headgasket but ran great, untill it shut down.