97 Engine Differences

OK I seem to be seeing lots of 5.7L engines out there for this generation of truck. Mine being a 5.0 I was wondering if anyone has the hp and gas mileage specs on both for comparison? Or even some real world experience between the two engines. Contemplating a possible new engine and don't know if I should stick with the 5.0 or switch to the 5.7

I don't have the information you're asking for but i think it would be smart to stick with the engine you have. I mean, you can do modifications to the existing engine, instead of getting a totally new engine. Also bigger engines tend to be gas hogs. What kind of truck do you have? (bed, cab?)

Well if you're going to buy a new engine anyway, then it would be a no brainer to get the 5.7L. I think your truck makes like 230 hp, and somewhere like 290 lbs-tq. The 5.7L is rated at 255 hp and 335 lbs-tq (both being Vortec engines now, and since your truck is a 97, then it is a Vortec).

Most everyone says the 5.7L gets better mileage then the 5.0L (I know this is true for the TBI engines, but I have no experience with the Vortec 305s). I do know a 5.7L Vortec engine will get close to 20 mpg in an extended cab Z-71.

And even if the 5.7L didn't get as much gas mileage (it will be close, either way) then the extra power would be enough for me (and if you've never drove a truck with a 5.7L Vortec, then you wouldn't understand, there is no comparison with the 5.0 and 5.7 engines). So I would go with the 5.7L engine if you were going to be buying an engine anyways.

Hope that helps.

I have a 1997 c1500 5.0 Vortec ext. cab.

I like the power and it is definitely enough for me. I drive pretty much all highway (90% highway / 10% city) and I get 18.5 - 19.0 mpg.

Obviously, if you have a free choice of one or the other, it would be a n-brainer to go with the 5.7...I wish that's what I had. But if you have a 305 motor there is no shame in that (at least that's what I tell myself so I can sleep at night).

How are yall getting 19 and 20 mpg on the highway. I can only manage 15 or 16 driving like a grandma on the highway and I have the 5.7 vortec.

How are yall getting 19 and 20 mpg on the highway. I can only manage 15 or 16 driving like a grandma on the highway and I have the 5.7 vortec.

I'd love to know the same! I have the 5.7 TBI and the darn thing only gets about 10-12 on highway or city driving wether I drive like grandma or hotrodding around town!

I have a '98 2 WD with the 5.7 Vortec. Last long road trip I got 21.7 mpg. That was at 70 mph, and the only diff from all stock is the air box cover off. No fancy intakes, exhaust or chips.

I'd love to know the same! I have the 5.7 TBI and the darn thing only gets about 10-12 on highway or city driving wether I drive like grandma or hotrodding around town!

You get 10-12 because you have a throttle body. Vortecs are a better fuel injenction, more advanced and harder to work on, but more fuel efficent than a throttle body.

There is no way you can get almost 22mpg in a 350 chevy when its only rated at 16mpg on the highway.

I don't know about all the difference in mpg. I have a 93 k1500 with 5.7 and it has always been in the 17 to 19 mpg range at highway speeds (or maybe a little higher)