Not really. Not by a long shot. The heads are totally different and much wider. That's one reason people incorrectly call them a "big block 318", which of course they never made. I've also heard them referred to as a "wide block" 318, which is somewhat accurate, since the heads do make the engine appear wider, but the LA and Poly blocks are basically identical in size and shape. When an LA and Poly are side by side, the differences really stand out. But yes, by far the quickest way to ID the difference is the number of valve cover bolts and shape of the valve covers, but as I said earlier, those are hardly the only differences.