1973 duster 340 valve intake

It all depends on the head. My personal opinion has always been that the factory 340s with the 2.02 intake valves were over valved. The head ports in stock form really cannot take advantage of the larger valve in well over 90% of the driving a stock headed 340 will see. As said earlier, it is all about velocity. Getting it in and out. With the right camshaft profile matched to stock unported heads, I believe the 1.88 valve would indeed out perform the 2.02 in most instances in a mild to moderate street engine. It's one thing if you already have heads with the larger valves. But I certainly would not go to the trouble and expense of installing the larger valves unless I was building a larger cube or way more radical 340. All of this really is a guess. The real truth would have to be seen on a flow bench.