Vintage Mustang Forums banner

Need help picking out stock valve springs 289

4950 Views 17 Replies 7 Participants Last post by  66coupe289
Hello I’m refreshing a 289 out of a 1967 mustang fastback for a friend of the family’s. Oppon disassembling the heads I found one of the original valve springs was broken. There’s two different types of valve springs available one says “ after L-10 to L-14” and the other says “after L-14 change” I honestly have no clue what this means and I need help picking out the right springs for the engine I’m working on.
1 - 4 of 18 Posts
For a stock engine, I would just use some quality aftermarket springs for a mild cam, like Edelbrock #5722. I would change them all.
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.
As a point of clarification, a valve spring can be changed with no impact on pushrod length.
@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.
I advocated for changing all the valve springs. At 50+ years old, plus one already failing, it's time. Cool info on all the "L" differences.
  • Like
Reactions: 2
Thanks !!! Just to be clear I need to get the springs that say “after L 14 change” correct ?
Go here:

They have the two valve springs you mention and under the description they give the outside diameter. Measure the diameter vs what you have. It should confirm the which ones you need.
1 - 4 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.