What's going on when car shift into 2nd?

[2toneNV]

This weekend I went to my local Saturday night car spot. On the way home a buddy of mine drove his '32 roadster and on the way home a Yellow GTO decided to play with him. I was behind them and got on it when they did and was reeling them in until after being in 2nd gear and right before it shifted into 3rd there was a pop almost like a misfire. The car stumbled and I let off then the power came back, but my buddy and I roled into our cars at about a 20 mph roll and the car did the same thing both times and about the same shift point. The last time I watched the scanmaster for knock. No knock, I am running 93 octane used a bottle of octane booster because the tank before was plus. I do not have ALKY. Any ideas, I didn't see any boost loss. I increased FP on SUnday and have yet to drive the car to see if it remedies the problem. No FP yet but will be next purchase. Have hotwire kit, new walbro and 60lb mototrons and TT chip. Any ideas?

 

[turbofabricator]

Plug blow-out? What spark plug gap and wires do you run? Did it over rev, and hit the rev limiter?

 

[2toneNV]

the plugs are the one thing I was gonna pull on Sunday but never did. The car did not over rev. I have MSD 8.5mm wires, the red ones.

 

[2toneNV]

bump

 

[87GNSteve]

Does your MAf have full range? reading correct?
4-7 at idle and 255 at WOT?