How different could the coil springs be (Inline 6 vs 302)

[bjde0b]

The inline six is a 4.9 liter and the 302 is a 5.0 liter. I know one is inline and one is a V. I recently bought new coil springs and they did not look the same. I konw that my truck came with an inline 6 so I decided to see if the springs were different for the different engines and they were.

The new springs are shorter (meant to be used with the 302 engine) than the old springs.

Not really much of a question, just seeing if anybody has any thoughts.

[Alvin in AZ]

Got access to a micrometer or a .001" reading caliper? :)
If so, measure the wire size of the springs and post 'em. :)
Where did you get the springs from?
A 302 is actually a lighter engine than a 300-6, did you know-ed that already? :)

Alvin in AZ

[bjde0b]

I didn't know the 300 was lighter.

I have picked up a digital caliper twice, walked to the counter, and then changed my mind. Now I have an excuse to buy one so when I do, I will post the numbers.

[bjde0b]

I measured my new and old springs tonight. I took two measurements on each. I didn't bother measuring each spring of the set, so the two measurements are from the same spring.

Old: 0.663, 0.665
New: 0.7, 0.702

I was suprised that the new ones are actually thicker. The new ones are black and my old ones are rust. I guess that is why they tell fat women to were black to make them look skinnier. I wanted to stiffen up the ride with new springs, but the old springs felt stiff when I put my 200 lbs on it. I know that probably doesn't tell me much. I just don't want to waste $80.

[FORDification]

And how thick is the paint on the new springs?

The F100 trucks had a 1055-lb spring for the I6 and an 1175-lb spring for V8s.
The F250 trucks used the 1175-lb spring for the I6 and had a 1250-lb spring for the V8s.
The F350 trucks used a 1365-lb spring for the I6 and a 1455-lb spring for the V8s.

What is the brand of spring and part number you ordered? It should have a weight rating that you can compare with these figures. However, since you're saying you wanted your truck to ride a still stiffer, and if the springs in your truck are still the original I6 springs and you replace them with the V8 springs, I'd think you'd be able to accomplish just that.

[Alvin in AZ]

I ordered heavy duty shocks and the build sheet has them listed and I
compared them to other new pickups and yes they were HD shocks.

About a month after getting the pickup the shocks were broke in good and
trying to drive across Willcox (has the water carrying dips either side of the
road at intersections) that sorry brand new sucker ('75 F150 360FE T18 2wd)
would bottom out and bounce around and almost make me sea sick. LOL :)

The dealership put the heaviest springs Ford makes, on it, under warranty.
One of the best things I've ever had done to my pickup! :)
They were trying to talk me out of the heaviest ones saying...
"they'll make it ride like a lumber wagon! :/" Etc. :/

Heck, I don't know what a lumber wagon rides like but it must be just like
a pickup with a nice-feeling firm-suspension because that's how mine's rode
ever since then. :)

I was into dual shocks too because the sorry sucker has always wanted to
dance sideways going down dirt roads without 'em. :/
Singled-up Rancho 5000's work too. :)

I've been messing with my pickup a long time. ;)

Alvin in AZ
ps- mine are now ~.740" left side ~.745" right side.
pps- the dealer installed a "factory set" and the left was ~.725 and
the right side was ~.740" and was never straight, the left side was
lower even with an FE+T18 on the right side.
ppps- I don't know pound ratings. :/
http://www.panix.com/~alvinj/file12/weights.jpg
I'm guessing mines' got the 3300 GAWR Front rating and so 1650-lb
springs and love 'em! :)
http://www.panix.com/~alvinj/file12/rideheight.jpg

[bjde0b]

That is more like the kind of answers I was looking for. I think I am going to stick with the springs that were meant for the v-8 since mine originally had the v-6. I know Alvin said the I-6 is heavier than the 302, I would think the springs would be stiffer, but the new springs did turn out to be thicker so they will have a higher k-value (enginerdery talk spring stiffness coefficient).

Besides you guys are helping me spend my money on new steering linkage, I might as well put in the new springs I already bought.

[Alvin in AZ]

http://www.panix.com/~alvinj/file12/coilsprings.jpg
The wimpy spring is taller and settles down to about the same length the stiffer spring will.
The stiffer spring is my old "weak" spring from the left side ~.725", they installed it in '75. :)
I remember the guy pointing out the purple stripe on it and saying it'd make it ride like a
lumber wagon. LOL :) To get 'im to shut up and install 'em I said "yeah, that's what I -want-
-lumber wagon springs-! :)".

That's a piece of 3/4" fuel hose I slipped over it years before as a hick version of an noise
isolator. {shrug}

Alvin in AZ