it also needed the spacer to clear the original 273/4 intake as the bores were smaller than those butterflys! But you got the spreadbore intake so no matter. Dont sweat the bore dimensions unless your rebuilding. we know its a 273 as it states it right on the block. The early 67 318LA blocks could have had the same casting number but used different 318 bore cores. would obviously say 2806030-318-2 or some other 318 core suffix. There should be a clock with a date casting on side of block too, I bet its a 66 date for a 67 model year. use a flashlight/borescope (Ebay, $12 hooks to phone) in the spark plug hole. you may be able to see the piston crown and number of valve reliefs. If you see the reliefs touching or very close, you got the 4bbl pistons. Score!
