TBI heads on 5.7 Vortec short block

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,892
Reaction score
13,597
Location
The Seasonally Frozen Wastelands
I just went through the thought-process of stuffing a Vortec short-block under TBI heads. In the end, I installed aftermarket aluminum heads because the TBI heads were damaged.

Using the "Vortec" short-block is easy. The Vortec short-block that I bought has the SAME casting number (880) on the block as the TBI engine I took out. The block is IDENTICAL except for a couple of machining differences--I had to drill a bypass hole into the water jacket to match the TBI water pump and water pump gasket on the right side of the block, and I had to drill and tap two holes for the two extra bolts that hold the TBI sheetmetal timing cover on.

Use the TBI damper to match the TBI timing cover/timing pointer.

Use Vortec pushrods to go with the roller lifters, dogbones, and spider. (Unless your heads have pushrod guideplates, in which case you'd need aftermarket hardened pushrods of the same length as the OEM roller-cam pushrods.)

Use the same oil filter adapter as the vehicle came with.

The Vortec oil pan, oil pump, and windage tray is the same as what was on my TBI engine.
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,892
Reaction score
13,597
Location
The Seasonally Frozen Wastelands
I had to drill a bypass hole into the water jacket to match the TBI water pump and water pump gasket on the right side of the block, and I had to drill and tap two holes for the two extra bolts that hold the TBI sheetmetal timing cover on..

Hey thanks Schurkey, that's very helpful to know.
Photo of two of the three holes you need to create. There's a second timing cover bolt hole on the opposite side of the block (not pictured.)

You must be registered for see images


Water pump comparison between Vortec and TBI parts:

You must be registered for see images


You must be registered for see images


Note how the Vortec pump/pulley has the belt positioned closer to the block than the TBI pump/pulley. Belt alignment could be a concern if mixing parts from Vortec and TBI accessory drives.
You must be registered for see images
 
Last edited:
Joined
Dec 10, 2016
Messages
518
Reaction score
160
Location
Hampton, VA
I just went through the thought-process of stuffing a Vortec short-block under TBI heads. In the end, I installed aftermarket aluminum heads because the TBI heads were damaged.

Using the "Vortec" short-block is easy. The Vortec short-block that I bought has the SAME casting number (880) on the block as the TBI engine I took out. The block is IDENTICAL except for a couple of machining differences--I had to drill a bypass hole into the water jacket to match the TBI water pump and water pump gasket on the right side of the block, and I had to drill and tap two holes for the two extra bolts that hold the TBI sheetmetal timing cover on.

Use the TBI damper to match the TBI timing cover/timing pointer.

Use Vortec pushrods to go with the roller lifters, dogbones, and spider. (Unless your heads have pushrod guideplates, in which case you'd need aftermarket hardened pushrods of the same length as the OEM roller-cam pushrods.)

Use the same oil filter adapter as the vehicle came with.

The Vortec oil pan, oil pump, and windage tray is the same as what was on my TBI engine.
Either that or drill a bypass hole in youe t-stat. Or you can also plumb in an external bypass like the vortec has. I run mine from under the t-stat, through the heater core, then into the water pump.
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,892
Reaction score
13,597
Location
The Seasonally Frozen Wastelands
Either that or drill a bypass hole in youe t-stat.
A common, but hateful mistake that lengthens engine warm-up. Yeah, it's better than not having a bypass at all.

Or you can also plumb in an external bypass like the vortec has. I run mine from under the t-stat, through the heater core, then into the water pump.
Yup, that can work.

If you're using the TBI water pump that's already set-up for a bypass hole, (due to belt alignment problems with the shorter Vortec pump) why reinvent the wheel when drilling one hole in the block brings you back to what the engineers did from 1955 to 1995?
 

ht89

Newbie
Joined
Dec 8, 2018
Messages
37
Reaction score
5
Location
43215
I'm not sure how the water bypass circuit works.
I under stand how the TBI pump/block/bypass is set up but how is the original Vortec pump/block/bypass set up?

I'd like to use the Vortec pump that's already installed on the Vortec block.

Now that I've got the truck home I noticed a short length of hose stub, terminated with a bolt, behind the water pump pulley, extending downwards to what I'm guessing is the top of the pump????
Does anyone have a pic of the front/top of the vortec pump?
Or any info in general about the Vortec water bypass set up?
 
Joined
Dec 10, 2016
Messages
518
Reaction score
160
Location
Hampton, VA
the water bypass is there to reciculate water inside the block before the thermostat opens. It prevents hot spots. And yes just run from under the tstat in the manifold to the water pump.
 

ht89

Newbie
Joined
Dec 8, 2018
Messages
37
Reaction score
5
Location
43215
Alright, thanks c1500deathtrap. Now all I gota do is drill & tap a pipe thread for a hose barb into the TBI manifold. Think I'll get one from the salvage yard to practice on. Then I'll post up a thread on how it goes.
 
Top