Vortec heads on 350

[82Scottsdale]

Ok well i got a free pair of vortec heads from my dad because he cracked a cylinder wall on his 5.7 vortec engine so, what do i need besides a carbed vortec intake manifold to put theses heads on my GM goodwrench 350 non vortec engine? will the rockers and everything else work out, and about how much power do you guys thing i will gain from them?

 

[4X4HIGH]

Make sure you use the rockers from the vortec heads as they are the self aligning rockers that must be used. Also if you must pass emissions testing you'll need to address the EGR issues.

 

[82Scottsdale]

i dont need emissions i already took my cats and stuff off and have headers, cant i get a non egr intake for it?

 

[4X4HIGH]

Yes you can get a carbed manifold for the vortec heads without an EGR. Here is a link to one. http://store.summitracing.com/partdetail.asp?part=EDL%2D7516&autoview=sku

 

[Thunder]

Any Vortec head to carb intake will be non egr.

 

[4X4HIGH]

Any Vortec head to carb intake will be non egr.

Not true. http://store.summitracing.com/partdetail.asp?part=NAL-12496820&autoview=sku

 

[USSkoval]

Any rockers from a head with centerbolt covers will work as they are all self-aligning.

 

[Thunder]

Not true. http://store.summitracing.com/partdetail.asp?part=NAL%2D12496820&autoview=sku

So how is EGR going to work with vortec head?
Vortec heads have no exhaust crossover.
It may have the EGR mount but it wont work without doing some plumbing. If you put an egr valve on that manifold. All it would be doing is plugging a hole.
I guess you could get the EGR kit for the Vortec to TBI and plumb it in to make it work.

 

[NorCalKid]

about how much power do you guys thing i will gain from them?

I am curious about this as well

 

[4X4HIGH]

Any rockers from a head with centerbolt covers will work as they are all self-aligning.

Not all centerbolt heads use self aligning rockers.

 

[4X4HIGH]

So how is EGR going to work with vortec head?
Vortec heads have no exhaust crossover.
It may have the EGR mount but it wont work without doing some plumbing. If you put an egr valve on that manifold. All it would be doing is plugging a hole.
I guess you could get the EGR kit for the Vortec to TBI and plumb it in to make it work.

Not sure how the exhaust plumbing works but at least there is a place for the valve and the intake passage is already there which will make it ALOT easier to deal with if anyone needs the EGR function.

 

[cmelo1050]

I am curious about this as well

I have heard claims of vortec hears adding 40hp. This is usually what summit claims in their catalog for they're GM performance heads.

 

[NorCalKid]

not to shabby, might have to look into finding me some

 

[b454rat]

I was gonna use this build up in my S-10 Blazer, but scrapped that idea, now it's gonna go in my 79 plow truck. This was just an estimate of what the motor would make, but whatever it is, would be a hell of a motor.

I'm using a 400 with the Vortec heads. Heads are rebuilt, screw in studs, guideplates, ports gasket matched, springs good to .550" lift.
Comp Cams Xtrme Energy 268, Edelbrock Performer intake, 454 TBI, headers of course.

Forgot to mention that this was gonna be injected, but would work just the same carb'd. With some work done to the TBI itself, bigger fuel pump, headers of course, and a custom chip to make everything work. Motor should make over 400 horse, and almost 450 ft/lbs of torque.

Probly these numbers will be higher with a carb with some tuning. I've heard 50 horse from just swapping heads. As soon as I get a job, get everything fixed/working on the truck, I'm gonna swap them over. Right now staying carbed, but have most the parts to convert over to TBI. Can't wait to put them on.....

 

[dyeager535]

There are magazine dyno tests on "stock" 350's that do back up the 40HP claims.

Of course, that's really going to depend on the engine itself...tune, cam, exhaust, original heads, induction, so many variations even from the factory, not every swap is going to yield the same gains.

 

[cmelo1050]

5700

The Vortec 5700 L31 is a V8 truck engine. Displacement is 5.7 L. It is the last production Generation I small-block from Chevrolet. The cylinder heads feature combustion chambers very similar to those of the LT1 V8, but without the reverse-flow cooling. As such, the L31 head is compatible with all older small-blocks, and is a very popular upgrade. It offers the performance of more expensive heads, at a much lower cost. It does, however, require a specific intake manifold (a Vortec head has four bolts attaching the intake manifold as opposed to the traditional six bolts per head). The L31 was replaced by the 5.3 L 5300 LM7. The 2002 model year was the final year for the L31 5.7 L small block V-8 whose origins date back to 1955. The Vortec 5700 is good for 255 horsepower and 330 lb·ft of torque bone stock. It is currently being produced for marine applications with minor modifications.
L31 applications:

• 1996-2003 Chevrolet Express/GMC Savana full-size vans
• 1996-1998 General Motors C/K full-size trucks
• 1996-1999 Chevrolet Suburban/GMC Suburban full-size long-wheelbase SUVs
• 1996-1999 Chevrolet Tahoe/GMC Yukon full-size short-wheelbase SUVs
• 1999-2000 Cadillac Escalade

TBI L31 applications

• 1996 G-series Vans over 8,500 GVW w/ 4L80E\

Special applications

• Oscar Mayer Wienermobile
• Isuzu Box Trucks

For anyone interested in swapping vortec heads this is just the wikipedia entry for the 5.7 vortec and what trucks it was used in. Hope this helps.

 

[Thunder]

​

5.7 Vortec Power baby!​

 

[USSkoval]

Not all centerbolt heads use self aligning rockers.

Really!? Which ones did not use them?

 

[4X4HIGH]

Really!? Which ones did not use them?

Some of the earliest centerbolt heads 86-87 did not use them. You can easily tell if you need self centering rockers by looking at the head where the pushrods go through, if the holes are round they must use the self centering rockers. If the holes are rectangular like all the earlier heads then standard rockers need to be used.

 

[82Scottsdale]

will the roller lifters swap over into my gm goodwrench block from the vortec block with out switching the cam when i switch the heads over?