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Discussion Starter · #1 ·
So I have a 96 Z-71 with a good 305 that well ... it is a 305 and does not have much power. I have heard that I can swap in a 350 short block and use my 305 heads, manifolds, accesories and such with no problems. Is this true, How well does it work, and Where can I get a VORTEC correct 350 short block that is both new and reasonably priced? Help is appreciated.
 

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Isn't the VORTEC only pertaining to the heads?

I thought the blocks were basically the same from 1957 to 1999 or whatever the run was.

In my understanding, the Vortec Head was/is a better mousetrap, and the injection is a better mousetrap, but the block stayed the same.

Lined up to buy a Vortec m'self, so will be following this thread closely.
 

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Has the motor been swapped??....... I always thought that 96 was the first year for the 350 vortec, chevy stopped using the 305 and went to the TBI 350 mid year in 1987. I have a friend that bought a new 87.5 becuase he could get the new 350 in the old body style.
I'm no chevy historian, but that's the progression as I know it:thumb:
 

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Discussion Starter · #4 ·
Has the motor been swapped??....... I always thought that 96 was the first year for the 350 vortec, chevy stopped using the 305 and went to the TBI 350 mid year in 1987. I have a friend that bought a new 87.5 becuase he could get the new 350 in the old body style.
I'm no chevy historian, but that's the progression as I know it:thumb:
Not swapped yet, I want to get it done after the first of the year though. And yes 96 was the first year of the Vortec, unfortunately the 305 Vortec was standard equipment in all half tons back then.
 

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Discussion Starter · #5 ·
Isn't the VORTEC only pertaining to the heads?

I thought the blocks were basically the same from 1957 to 1999 or whatever the run was.

In my understanding, the Vortec Head was/is a better mousetrap, and the injection is a better mousetrap, but the block stayed the same.

Lined up to buy a Vortec m'self, so will be following this thread closely.
In my understanding a Vortec Correct Block does not have the port on the block for the manual fuel pump because the Vortec requires Higher and more constant fuel pressure supplied by an electric fuel pump. I believe the heads and Manifold are all interchangeable on similar year Vortec Motors. I am kind of worried about what the different short block will do to the computer and such.
 

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If I understand your question correctly...
Yes the heads and manifolds from a 96 small block will bolt onto an earlier small block. The "Vortec" refers to the heads and they have a different intake bolt pattern than the older small block heads. It is said that certain "Vortec" heads will flow better than any other production small block head. But it is a certain part # and I don't have those #'s with me. I believe they are identified by a sawtooth pattern on the end of the heads(not sure)

The short block has gone thru some minor changes thru that time. Mainly the deletion of the machanical fuel pump boss and the changing of the rear main seal to a one piece design. If you are going to fuel inject the motor anyways then you wil be using an electric fuel pump so that won't matter. But the one-piece rear seal crank uses a different flywheel/flexplate bolt pattern so watch for that.

I believe in '98(not sure) chevy went to the roller cam in the truck engines, that brought other changes to the block, but unless you were planning on running a factory roller cam that won't matter either. But having a later block that is roller cam compatable is not required to run "Vortec" heads and intakes.

Hope this helps...
 

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I have known other people that have done this and didn't change a thing just took a longblock 350 and put all the stuff off the 305 in it. The wiring is going to be the same. I would think at most you would need a new computer. I also have known poeple who have swapped vortec heads on similar years as yours one person said the computer took about a week to figure it out but after that no problems. No check engine or anything. The computers are very sensitive to the amount of vacum the engine has hence the cam is important. If you change the cam get a computer freindly one. Do a little research around and you will find poeple who know a whole lot more than I do.
 

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chevy stopped using the 305 and went to the TBI 350 mid year in 1987.
I'm no chevy historian, but that's the progression as I know it:thumb:
As in dropped altogether?

No, offered it for years and years to come, had one in an early 90's buick, One of the salesperson's at Cole when I worked there was the laughing stock, cause his brand new (1998) Vortec Z71, that you HAD to have if you sold Chevy, (gang thing, I dunno?) had the 305. Only like 30 horse difference, not sure why it was that much of a big deal, but it was a Fruedian cock fight none the less.
 
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