Need help picking out stock valve springs 289

Yes, @awhtx is correct. The "L" refers to the change level (revision number) of engine. Knowing the change level is a must if you are only replacing certain parts, particularly valve train parts like valves, rockers, springs, etc. As stated and assuming the engine has the original engine tag, you can find the change level on the engine tag. Otherwise you can identify the change level by examining the parts used when the engine was put together at the factory. That's assuming that someone already didn't tear into the engine resulting in a mish-mash of parts. Bob Mannel's Mustang and Ford Small Block V8 book is indispensable in this respect. Keep in mind, just because you are pulling a 289 out of a 67 doesn't mean that the engine was produced during the 67 model year. Also, make sure you check for the correct push rod length if doing any machining of the heads or block and/or changing any valve train components from stock.

EDIT: @Archer meredith just saw your post. Having the engine tag is a good start. Try to verify that its original to the engine just to make sure.

@66coupe289 I agree but I would not mix and match different spring sizes.

There was variation in stock spring sizes through the life span of the 289 which could affect performance and longevity if mixing parts from different change levels. Particularly between change Level L9 (larger spring) and change level L10 (smaller spring). Now to blow you mind Ford switched back to a larger spring for change level L14.

In my opinion and putting aside the 289 HiPo, the biggest change level for the 289 was between change level L9 and L11. There were considerable changes to the valve train. If you really have a 67 289, I'm guessing it would probably be change level L12 or L14 (I don't think there was a change level L13.). Of course all of this is irrelevant if putting on a new top end (heads, valves, rockers, cam, etc.). You can always do a custom engine build just make sure the parts play nice together.

As an FYI NPD lists 2 springs that can fit a 67 289. Part # 6513-3 (Change level L10 up to but excluding L14) or Part # 6513-4 (From change level L14). You just need to know the year of you engine and change level if staying with the stock setup.

Another great book to get is How to Rebuild Small-Block Ford Engines by Tom Monroe.