vortec 305

[79rustyk10]

What the opinion on them?

Since the previous DD died and I have no idea how much longer this car will go, I hope to get a truck some time this spring. looking on craigslist and found a few 97-98-99 OBS with the 305 that are pretty clean. Just curious if they are even worth considering vs the 350.

 

[dfl701]

I had one in my 96 and loved it. I was getting 18 mpg before the lift and tires

 

[sweetk30]

first gen vortec = great dd.

but dont put any money in it for power adders.

i dont care for them. just go 99-up 4.8 5.3 6.0 and be done with it.

 

[79bonanza]

i disagree, the 5.7 vortec can be built to make like 400 hp with a mild build up and a cam ( turning it to a carbed engine) id buy one with no hesitation as to if it will last

 

[Stomis]

i disagree, the 5.7 vortec can be built to make like 400 hp with a mild build up and a cam ( turning it to a carbed engine) id buy one with no hesitation as to if it will last

I think he meant dont put money into the 305 part. Its a well known fact that 350 vortec heads make some of the best junkyard heads for a small block.

 

[max 02]

Had a 98Z71 that we bought new in 99 drove it for 80 thos klms and traded it for a new duramax in 02, loved the Z71 but love the dmax way more. The Z71 had a350 in it and got around 19 miles to the gal..US. Nice trucks ,still like them ,but wasn`t what I need. I dont know if that is of any value to you,but if you can find a nice one I think you would be happy.

 

[sweetk30]

i disagree, the 5.7 vortec can be built to make like 400 hp with a mild build up and a cam ( turning it to a carbed engine) id buy one with no hesitation as to if it will last

thats a hole other thread topic here.

 

[79bonanza]

haha oops must have missed the 305 part

 

[Cornfield creations]

I have a 98 w/ a 350. Love it. The fuel injection system is problem ridden, as long as you use fuel injection cleaner regularly it should give you good service. Power wise, in a 1/2 ton they are great. I love the OBS more than any of the newer ones.

 

[79rustyk10]

I have a 98 w/ a 350. Love it. The fuel injection system is problem ridden, as long as you use fuel injection cleaner regularly it should give you good service. Power wise, in a 1/2 ton they are great. I love the OBS more than any of the newer ones.

I hear/see mixed things with the injection system. Ive seen nice low mileage trucks need constant attention, then Ive seen friends beat and abuse these mercilessly and have to do the intake gaskets maybe once. Ive always thought after seeing how it works that the injection system is kinda half assed.

This is also my favorite body style as well, with the 99-02 body a close second. I guess Id rather find a clean nice older truck, than one thats newer but not maintained as well or abused if that makes sense.

 

[Chevy305]

the vortec 305s will run forever and power isn't horrible either. Just think a vortec 305 still makes much more power than a factory carbed K5 350.

 

[Cornfield creations]

I hear/see mixed things with the injection system. Ive seen nice low mileage trucks need constant attention, then Ive seen friends beat and abuse these mercilessly and have to do the intake gaskets maybe once. Ive always thought after seeing how it works that the injection system is kinda half assed.

This is also my favorite body style as well, with the 99-02 body a close second. I guess Id rather find a clean nice older truck, than one thats newer but not maintained as well or abused if that makes sense.

Well it's inside the upper manifold. They used the injectors higher up where the big plug in is, then they ran hoses to poppet valves down into the intake. The poppets and hoses got clogged with carbon and gum a lot. Then they would stick open or closed, or the hoses would get clogged so fuel barely came out.

They have an upgrade that converts it to multi-port, where it puts the injectors down into the intake where the poppets would have been. I have heard of better running but myself I have never done the conversion.