fulltilt
Registered Member
i just picked up a set of vortec heads 906's and want to put them on my 90 k5 tbi, now i know i need a new intake manifold but i also need to pass emissions so how do i get around the egr issues?
CK5
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vortec heads
- Thread starter fulltilt
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Cornfield creations
1/2 ton status
Keep in mind, you have to run an external coolant bypass from the intake to the water pump as the vortecs do not have those built in like the older style heads. I have a GMPP intake for a quadrajet, and I think they made one for the TBI if you decided to still use it. They have EGR bosses on the pass side of the intake, that routes to the driver side next to the thermostat housing if you decided to use the factory 96-2000 manifolds and EGR tube. I'll see if I can find my GMPP catalog with the part numbers.
fulltilt
Registered Member
12496821 i belive is the part #
as far as the cross over for the water i thought the only difference would be the heater hose going to the front of the manifold on the vortec setup instead of the rear on the stock tbi head set up
just for reference i was planning on using the edelbrock 7116 manifold
as far as the cross over for the water i thought the only difference would be the heater hose going to the front of the manifold on the vortec setup instead of the rear on the stock tbi head set up
just for reference i was planning on using the edelbrock 7116 manifold
Cornfield creations
1/2 ton status
It won't relieve enough pressure, just redirect it. You can run the heater hose on the pass. side of the intake, but you have to run one from the front to the water pump to relieve the pressure under the thermostat. Otherwise you will have mad cooling issues. High spikes and water pumps, heater cores, and radiators blowing leaks. Ask me how I know.
The older heads have the bypass built into the heads, vortecs don't. Thats why we have to put an external bypass in.
The older heads have the bypass built into the heads, vortecs don't. Thats why we have to put an external bypass in.
I've read a few stories about people not running the bypass, they were all ugly.
I've got one my GMPP 383 which has vortec heads.
I've got one my GMPP 383 which has vortec heads.
Possible hijack, but related:
Maybe that's what I have going on, I bought a set of vortec heads and not even thinking about it, bolted up my TBI intake, and off I went. Cooling system seems to pressurize quickly. How do verify what heads I have and what do I do about it if I do have the vortec heads bolted to a TBI intake?
Maybe that's what I have going on, I bought a set of vortec heads and not even thinking about it, bolted up my TBI intake, and off I went. Cooling system seems to pressurize quickly. How do verify what heads I have and what do I do about it if I do have the vortec heads bolted to a TBI intake?
fulltilt
Registered Member
well one thing is for sure, a stock tbi manifold will not bolt on to vortec heads
i have heard of people getting the vortec heads drilled to acept an older manifold, but you will still run into another problem when doing so, and that is the intake runners on the vortec heads are taller so you will need to weld extra material onto the manifold and then grind the intake ports on the maifold to match the heads
man i have heard so many good things about these heads, but they just seem to be a big pain in the a$$, and i think i will use the 492's i have instead
i have heard of people getting the vortec heads drilled to acept an older manifold, but you will still run into another problem when doing so, and that is the intake runners on the vortec heads are taller so you will need to weld extra material onto the manifold and then grind the intake ports on the maifold to match the heads
man i have heard so many good things about these heads, but they just seem to be a big pain in the a$$, and i think i will use the 492's i have instead
IF you put a stock manifold back on and it all bolted up, you don't have vortec heads.
Cornfield creations
1/2 ton status
DITTO.
Vortec heads will show an increase of about 30-40 HP over stock heads on the older engines, but you have to run a vortec specific intake and low torque o-ring graskets. 11ft lbs. 8 bolts instead of 12 and they go straight down instead of at an angle.
I love my vortecs. For a low budget upgrade they can't really be beat. Just make sure you have all the right parts and everything in place so things don't get ugly as I found out.
Vortec heads will show an increase of about 30-40 HP over stock heads on the older engines, but you have to run a vortec specific intake and low torque o-ring graskets. 11ft lbs. 8 bolts instead of 12 and they go straight down instead of at an angle.
I love my vortecs. For a low budget upgrade they can't really be beat. Just make sure you have all the right parts and everything in place so things don't get ugly as I found out.
does anyone have a pic of this coolant bypass? I am running a 400 small block with steam holes drilled into the heads, would this still be applicable in my situation? I just went and looked at my truck and I only have a hose comming out of the intake on the passenger side and going to the heater core. FYI I have edelbrock performer rpm airgap intake.
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IF you put a stock manifold back on and it all bolted up, you don't have vortec heads.
Thanks,
