1978 401 Valve Springs Help

[Wagoneer Taylor]

Hey guys,

For some reason I am having a heck of a time finding valve spring info.

More over, what is stock specs?

If anyone can point me in the right direction or let me know what you used?

I am building a completely stock 401 internally, but I would like to use dampened springs.

Thanks,
Taylor

[Cliff]

My 1981 Chilton's manual has valve spring specs for the 401 but only up to 1974. It's an "auto" manual so it doesn't include Jeeps, and 74 was the last year for the 401 in cars. But I can relay the 74 specs if you think it will be of any value.

[Wagoneer Taylor]

My 1981 Chilton's manual has valve spring specs for the 401 but only up to 1974. It's an "auto" manual so it doesn't include Jeeps, and 74 was the last year for the 401 in cars. But I can relay the 74 specs if you think it will be of any value.

Thanks Cliff, I am sure it couldnt hurt to have the specs on 74.

Please share.

[SC/397]

You might be able to find it faster if you looked up valve springs for a 360.
The 360 and 401 use the same cylinder heads.
For a stock application, I usually buy these and eliminate the rotators.

https://www.ebay.com/itm/221346985073

I will see if I can find more info for you.

[Wagoneer Taylor]

You might be able to find it faster if you looked up valve springs for a 360.
The 360 and 401 use the same cylinder heads.
For a stock application, I usually buy these and eliminate the rotators.

https://www.ebay.com/itm/221346985073

I will see if I can find more info for you.

Hey SC/397, I should have reached out to you! You having built about a million on these.

Do you use or know of a set that has the damper in them but would be a nearly stock pressure?

I will look into 360 springs as you mentioned too

[Wagoneer Taylor]

You might be able to find it faster if you looked up valve springs for a 360.
The 360 and 401 use the same cylinder heads.
For a stock application, I usually buy these and eliminate the rotators.

https://www.ebay.com/itm/221346985073

I will see if I can find more info for you.

Another question, why do you eliminate the rotators?

[SC/397]

I guess the main reasons I eliminate the rotocaps is because the early engines didn't have them and because it is harder to find the shorter springs.
Also, there is less of a problem with coil bind if you are using a slightly higher lift cam.

[Wagoneer Taylor]

I guess the main reasons I eliminate the rotocaps is because the early engines didn't have them and because it is harder to find the shorter springs.
Also, there is less of a problem with coil bind if you are using a slightly higher lift cam.

So the springs you sent in the link are longer then stock?
The problem I am having is I dont even know what size I should have in the first place?
I am running a stock cam.

[Cliff]

I had mentioned that my Chilton's only included the 401 up to 1974, but I was wrong - it goes to 1976. Here are the specs:

outer spring test pressure 223 lbs @ 1.35"
spring installed height 1-13/16"

There is a separate spec for police engines:

outer spring test pressure
intake 270 lbs @ 1.38"
exhaust 270 lbs @ 1.19"

The test pressure specs for 1976 360 CID are 213 lbs instead of 223, same height

[SC/397]

Those specs look about right. 1.800" installed height and around 100# on the seat. I think the lighter ones may have been around 80# on the seat.

[Wagoneer Taylor]

Thanks guys, this is helping me narrow it down at least.

[rang-a-stang]

[Wagoneer Taylor]

I dont know whether to laugh hysterically or

I am going with laugh!

[SC/397]

This is a really good How-to vid for you.

https://www.youtube.com/watch?v=oFX_Xq9WHTI

[Wagoneer Taylor]

This is a really good How-to vid for you.
https://www.youtube.com/watch?v=oFX_Xq9WHTI