smoking hard out left bank

well got the whole upper end off now and ready to pull saterday . first post smoking left bank came up with 1 chipped piston and 3 eggshaped gasket holes #1 was chipped.
today got the right side tore down , and found # 8 chipped and ^ was egged shaped in gasket slightly. so now wondering if I found the breathing potentials of stock manifolds ??
don't know y most damage was on passenger bank the drivers side has that funky manifold .it is a 65 Barracuda with a built 360 with stock manifolds .
my first guess was to much timing or over reved
2nd best answer I got was rings not properly filed to fit , may have been to long , to tight .
what is the proper # I should file the new 1ns too ???? to fit proper in a warm motor?
I"ve never had this happen to any motor before ..
all new pistons and rings coming , so I will have 6 pistons for sale $ 150.00 shipped
I just don't want this to happen again , also I will be putting in cometic gasket for heads
the rest felpro .
anymore info is appreciated from professinal builders or would like to hear your storyand answer if you had happen and had or fixed to shed more light .
here are some pics of the right bank followed again by the left I caught smoking on upper and of the run figured if 1 went as hard as the left bank did there had to be damage on the right side. Funny neither broken pistons had any compression lost . figure $700.00 in damage , No sign of valve damage but replacing # 1 and 8 exhaust valves anyways , just incase ,+ guides will be inspected or replaced . Thanks for responding with insight help people
hope to be back running before memorial day weekend if not next week. THE BARRACUDA"S 53RD BIRTHDAY.

100_2054.JPG

100_2055.JPG

100_2056.JPG

100_2057.JPG

100_2050.JPG

100_2046.JPG