How much **** power does a 5.7 put out compared to a 5.0? Which is the stronger motor? When it comes time to replace my 5.0 should I get a 5.0 or a 5.7 crate engine?

 

5.7 is a chevy 350. the ford 351 is a 5.8. the 351 has a lot more torque, little more power. I had a truck with a 5.0, totalled it and now my truck has a 5.8. It has a lot more umph but is bad on gas compared to my 5.0

 

Well my 5.0 gets about 15mpg and I am impressed with that but would a 5.8 be that much worse ? Is the mpg difference worth it for the power?
I have had Chevy Motors in 2 cutlass and a monte carlo and I would not even compare the 305 to the 350 the 350's I played with worked better and were easier on gas than the 305 my guess was the moter did not work as hard . Is this not the same case with the ford 302 and 351? Which of these 2 motors can be drove harder which one is tuffer?

 

The 305 is no comparison to the 302. Never had a problem with the old '85 305 C10 we had, but the 302/351 and 350 chevy are all equally strong motors.

Adrianspeeder

 

Anything a 302 can do the 351 can do with ease. It is a much stronger engine. Unfortunately, the 351 has a well deserved reputation for having a drinking problem. If you're getting 15 now (and that's rather poor mileage for a 302) and the mileage is due to your driving habits rather than the state of repair/tune of your engine then expect something on the order of 12-13 if you drive the 3511 the same way.

 

There is no replacement for displacement. the larger motor will always perform better, last longer, and use more fuel.

 

My truck runs great and the motor doesnt seem to care how hard I drive it, the gas millage doesnt seem to change that much,unless you drive in town with it not like my old 4.9 it went from bad to worse if you were driving it hard. I had a friend tell me that he thinks that the 5.8 will be noticeably alot harder on gas than my 5.0 if you hold it wide open for a few miles, where as the 5.0 is more consistante with its gas millage even if you are driving it hard.
has anyone else noticed this?

 

i got 16mpg on my 5.8 1995 f-150 without a tonneau highway trip.

ive also got a 302 powered car- both are great motors but i got a 351 in the truck for towing ease.

the 351 is the 302 with a taller deck. lots of stuff, including heads, are interchangeable.

 

Are you saying that the heads, intake,throttle body are all interchangable for the 5.8 to the 5.0. Is this true? I was told that nothing was interchangable on these 2 motors unlike the Chevy which I am more firmiler with.

 

I took the 302 out of my old Grand Marquis and put in a 351. The difference in torque is amazing. I didnt really notice much difference in mileage unless I was really giving it.

 

The heads will change over, the intakes will not because of the deck height of the 351 being greater.

The 351 makes more torque but not much more horsepower. This is in my opinion due to the limitations of the heads. The 351W has a bigger cam than the first gen Lightnings, but makes less power due to crappy flow through the stock heads. Since it's easier to fill a smaller cylinder, the 302 makes almost as much HP with less cubes.


From my experience the 351 will always consume more fuel, especially when the revs are up. For towing it will equal the two out some, since the 302 will need to downshift sooner because of the lower torque output.

 

So is there an advantage of swapping my 5.0 heads for the 5.8 heads ( that I don't have) or should I put the money into rebuilding my 5.0 liter heads with aftermarket parts that will make them work better?

 

Sorry for bad wording. The heads are the same, unless you consider the Lightning (1st generation) in the mix. My post was intended to show that even with a larger cam lift and more displacement, the 351 doesn't make much more power.

You can get GT-40 or GT-40P heads from Ford, or any of a lot of different aftermaket heads. The 40P head require a different exhaust due to angled plugs. If you get lucky you can find either for a fairly cheap price.

 

thanks I am just trying to figure out weather or not it is worth my bother to try and find a 5.8 and build it or build my 5.0. If this was a Chevy small block no questions, hands down I would build the 350 and use the 305 for land fill. But no one has ripped appart the 5.0 liter the ony thing I have heard is a little more horse power and alot of torque difference out of the 5.8 and alot harder on gas but I would guess you could likely get alot more torque out of these 5.0 liter's once you start putting a cam and heads on it. My truck will take a 2000 5.4 liter Chevy off the line now but once we get going he can play with me, I don't like that! Should I build a 5.0 or a 5.8? my buddy has a wicked 91 chevy 4x4 with a done up 350 in it I would like to be able to compeat with that, should I go the 5.8 since I have such high expections out of my truck or will a 5.0 be able to do the job ?

 

When people talk about small HP differences between the 351 and 302 they are talking about peak power. At peak the truck 351 only makes something like 10-15 HP more than the truck 302 but it makes significantly more HP than the 302 throughout the rest of its range. By the time it gets to the HP peak, the crappy stock heads have run out of breath therefore the minor peak power difference. Lower in the range the 351 may develop 30 or 40 HP more than the 302 at any given RPM. The result is a much quicker, stronger and more drivable truck.