vortech heads 96-02 best ones ?

[hadmtrst]

which one are the most desireable? crackprone? flo best? 602 crate for oval track?street performance ?any other suggestions are welcome thanks howard

[F-BIRD'88]

The best of the L-31 oem vortec heads were cast from 96 to 2000 in St. Catharines, Ontario.
The casting number on the heads ends in 062.
There is a machine stamped on casting production date number near the exhaust ports but its real hard to see on a rusted head.
After that they were cast in Mexico.

These heads are not crack prone per say but many of the truck engines suffered from coolant loss (intake manifold gasket leaks) and overheating
which resulted in engine failure and cracked heads. Its the OEM overheating problem that cracked the heads, not the heads.
Thats why many of them you see for sale (ARE ALREADY CRACKED , cause they are off fubared overheated motors.
Good heads get rebuilt, not sold off.
If you buy new from GM they won't crack. (unless you also severly overheat your motor)

The more recent Mexico casting have smaller intake ports and are down some 10cfm from the early good Canuck 062 heads
which flow 228 @28" (my test)

But you can hand port the mex heads to fix that.

There is also a 906 casting vortec head that was cast in the USA and its not bad. Some HD/marine versions have a pressed on hardened exhaust seat. These need hand clean up to blend the casting bowl into the seat and a high per 3 angle or radiused ex valve job. as they have a single angle non perf ex valve seat valve job.
Other than that they are fine.

They all flow a lot more once hand ported with 2.02 x 1.60 valves

The new most recent GMPP Bowtie big port/ and small port Vortecs are way ahead of the game.

If you are buying new and want a true high perf, high flow high power vortec style head, buy these.

use the felpro 1255 intake gasket. Use a vortec style intake manifold.

Used-ebay second hand Vortec heads MUST be checked for cracks. Thats why they are no longer attached to the OEM vortec engine they came from. Remember good heads are not stripped from a good motor and sold.

We used to get the good heads cheap , here., new... back in the day.

[CNC BLOCKS]

which one are the most desireable? crackprone? flo best? 602 crate for oval track?street performance ?any other suggestions are welcome thanks howard

Any of the 906 or the 062 casting have worked the best for me for circle track applications, The Mexican castings have to of intake runners. 2.000 intake valve is the biggest you want to go with.

[novadude]

I don't know that ALL of the Mexican heads are bad. I have untouched Mexican 062s that went 227 cfm on the intake. Never measured port volumes.

[CNC BLOCKS]

I don't know that ALL of the Mexican heads are bad. I have untouched Mexican 062s that went 227 cfm on the intake. Never measured port volumes.

Any of the Mexican castings port volume has been around 159CC compared the non Mexican castings being at 170CC

Found out the hard way had a circle track engine on the dyno CFM was down and about 35 horse off checked the runners on the Mexican casting and they were 159, Went to the 906 casting everything was fine.

[T-flow]

I have also used & ported them all, the 906's seem to be the best. The dirt track guy's have helped with my conclusion...

[Schurkey]

A buddy of mine is an automotive machinist. His comments to me--years ago--is that the machinework on the castings as installed on vehicles is fine. The machinework on the parts-counter "replacement" heads is suspect.

What is the opinion here of the machinework quality of the "in-the-box, over-the-parts-counter" replacement Vortec heads?

[wyrmrider]

I recommend blueprinting all new heads
There are some recent pictures on Speedtalk showing why
the flashlight showing under the closed valve is a dead give away.
I od hone all the vlaves first finding bad valves
and check the guides, usually knurling and reaming/ honeing
mostly for oil retention but any bad guides show up
The touch up the valve job- or more if necessary
check the springs and spring heights
etc
cc the end cylinders and equalize if necessary

[SLPRACINGENGINES]

yes you are right..i have to use alot of thee heads in certain classes.i have had three or four set that the valve were way off and had to start fron stratch on them..this mess gm is selling is mostly casted in mexico and there is no q/c to it.useless you have to run them in a class to me your dollars and performance ahead of the ball game buying a good set of heads. i have also had some recent problems with some dart casting that were complete assy heads ..customer installed them on there engines and then come dragging them into my shop for me to fix them.i actually had one set i sent back to dart wouldnt even get into trying to fix them.

[maxracesoftware]

which one are the most desireable? crackprone? flo best? 602 crate for oval track?street performance ?any other suggestions are welcome thanks howard

some examples

Dyno tests of various Vortec Head versions :

4.060x3.490=361.5 cid

Rules :
any type Valve Job as long as
all Valve Job cuts are done by a Cutter

absolutely no Port matching or Porting
and any part of Ports or Chambers

Any Valve Sizes OK to use

Flat Top pistons only

any amount of straight or angle-milling allowed


we won local Mud Track 2012 Championship
with these 2 different Heads during 2012 year
#062 2.055/1.600 = 458 HP

#906 2.055/1.600 = 478 HP


then won 2013 local Mud Track 2013 Championship
( Legal 062 casting number on Head )
EQ Vortec 2.055/1.600 = 501 HP


then about to win local Mud Track 2014 Championship
( Legal 062 casting number on Head )
ProMaxx Vortec version 2.055/1.600 = 526 HP



**********************************

[foxchassis]

Larry M
Did you happen to flow any of the above heads to see differences in valve dia. and valve job?

Dwight Fox

[maxracesoftware]

Larry M
Did you happen to flow any of the above heads to see differences in valve dia. and valve job?

Dwight Fox

Edit: Correction -> the EQ Head has #906 casting number "definetly" on it
( and the ProMaxx has #906 cast on it also )

hi Dwight ,
yes i have all the Flow numbers
all the Heads had same 2.055/1.600 valve combos 5/16 stems KLine Guides
same Intake 38/45/75/90 45deg VJ .040" width seats 30deg Int Valve backcuts
radius valve job on Exhaust side 45deg VJ .040" width seats ( no Exh valve backcuts )

but starting with EQ Heads a little deeper Bowl Cutter was used

then with ProMaxx Vortec , even a better deeper Bowl Cutter was used
along with new Chamber Cutter on both intake and Exhaust sides

our then new out-the-box #906 Vortecs Stock 1.940/1.500 Valves no backcuts flow tested = 216.8 CFM @ .550" / 137.1 CFM Exh No-Pipe 4.030 Bore Fixture
#906 ended up Flowing a little better than the #062 ( HP was 478 vs 458 ) ( #906= 232.6 CFM @ .550" / 155.5 CFM Exh No-Pipe 4.030 Bore Fixture )
the EQ flowed better than #906 ( Hp was 501 vs 478 ) ( EQ Head = 233.6 CFM @ .550" / 189.9 CFM @ .500" Exh No-Pipe 4.030 Bore Fixture
the ProMaxx flowed better than EQ ( HP was 526 vs 501 ) ( ProMaxx = 249.1 CFM @ .550" / 173.9 CFM Exh No-Pipe 4.030 Bore Fixture )

the Heads had different CSA and Port Volumes out-the-box
the ProMaxx was largest

same out-the-box Edlebrock RPM Air Gap dual plane manifold used
also a new GM dual plane manifold was tested but lost 6 Peak HP and 3.5 Peak TQ from Edelbrock , avg TQ and HP was also down

Cam per Rules is Flat Tappet Hydraulic ( no Roller Cams or Solid Lifters allowed )

must make 17" Vac at 1000 RPM
we used Rhoades hyd lifters

must use stock Rods , Crank, Block )
out block is "Hencho en Mexico"

Dwight for more Vortec Head info
these Threads are for "Ported Vortec Heads" in various states with different valve sizes

viewtopic.php?t=12543

viewtopic.php?p=13834&highlight=vortec#13834

viewtopic.php?f=1&t=1880

viewtopic.php?f=1&t=1880&start=15

[maxracesoftware]

all the Heads had same 2.055/1.600 valve combos 5/16 stems KLine Guides
same Intake 38/45/75/90 45deg VJ .040" width seats 30deg Int Valve backcuts
radius valve job on Exhaust side 45deg VJ .040" width seats ( no Exh valve backcuts )

Edit Correction :
Wrong-----> Intake 38/45/75/90 45deg VJ
should be--> Intake 38/45/60/75/90 45deg VJ