Add the Apten or "Crack Pipe" mod to the rear of the driver's head, and that will be a thing of the past.
#7 and #8 are always the cylinders I have problems with; they detonate first when you're tuning, setting the deal for the rest of the engine.
The 4.6 iron block that I recycled had #6, 7, and 8 clearances getting bigger as it went back; #8 was 4 mils over in the middle of the bore, kinda like a barrel.
#7 was wider at the top, lol.
All the other ones were close to stock; that had to be heat.
As a contrast, the Teksid engine I bought measured 3.552 -.0001 to 0.0006 inc. on all axes, all the way to the bottom of the sleeve.
It apparently got fed enough quaker state to choke it out, with one imrc open, and one closed.
Judging from the rear end damage of the donor car, it doesn't accelerate very well that way.