Aluminum heads

good investment for later especially if your stock heads are tired
check your timing chain and check cam while you are at it
IDK about air gap on a stock compression 318 or do you already have it- how's it working 4 U
headers? gears, etc please
report how far down the hole and calculate true compression
.028 gaskets?
run a compression test before and after and report please
MERRY CHRISTMAS send Santa MyWay