Adding Vortex motor in 94 truck

[Marv D]

Originally Posted by sntrym95

Here are my notes from the swap:

GM TBI to Vortec manifold 12486572
Driver's side exhaust manifold or headers with EGR tube. I'm going with Gibson GP102S (if you care about EGR)
EGR tube for Vortec 10242876 (Dorman 598-200) (if you care about EGR)
Chip kit from tbichips.com - pcm chip, 18psi spring (see fuel pump note below)
Intake bolts (8) - 12550027
Intake gaskets - MS901312
Dizzy with melodized cam gear - https://www.summitracing.com/oh/part...0200/overview/ - I couldn't find the gear with my shaft diameter (.0430) so I bought a new dizzy with the correct gear
3/8 npt to 1/2" nipple right angle - for brake booster. I used a 1/2" heater hose to connect from the nipple to the brake booster
Valve cover grommets (2) 3989350 - just a replacement of worn parts
Fuel pump assembly - 19153722 - I needed the entire assembly for the 4 door Yukon. You will just need a higher volume fuel pump. TBIChips.com has a kit with the pump (see note above)
2x -5/8 nipple to 1/2npt 90 degree (for coolant - you'll need to put in a bypass as the Vortec heads do not have the provision. For the manifold I used, I ran a hose from the front top hole to the heater core, the heater core to the radiator, and the rear top hole on the manifold to the water pump.
3/4" freeze plug for the timing cover where the crankshaft position sensor would go. A little rtv, tap it in gently. If you don't use the Vortec timing cover, you don't need to do this. The motor I bought was already assembled as a long block.
Some 5/8 and 1/2 hose, clamps, vacuum hose, etc.

All of the accessories bolted up no problem. The one bar support for the tensioner doesn't fit since you are using vertical bolts instead of angled. I haven't made anything for it yet, but it doesn't seem to need it.

For the MAP sensor bracket, I had to cut off about 3/8 of an inch then drill another 5/16 hole in it to mount it with the manifold to head bolt.

For the throttle cable bracket, I had to fold the bottom plate over 180 degrees and bend it a little to get it to fit where the manifold to head bolt goes. I think I had to trim it a little too. I thought about using the 96-99 throttle bracket, so I picked one up from the local boneyard, but the clip sizes are different and it wont work unless you swap the clips.

Other than that, it's not too bad. I have noticed big improvement in acceleration - mostly just smooth and quick if you're on throttle just a little. I added an AAM TracRite posi and it will spin the tires easily if you gun it. Mileage is probably not as good as it was, but it definitely pulls better than the TB I motor.

Pretty much the same encountered here but my Vortec is stroked, 383 with RHS Vortec iron heads, and I used a Holley 670cfm throttle body on that same intake as sntry, (had to bore the intake for the larger throttle blades of the Holley TB but that's no biggie) The Holley TB accepts a JET adjustable fuel pressure regulator and used the stock 94 fuel pump. Stock PSI for the 94 TB is 9-13 psi.
All of the stock accessories and everything bolted up file, except for the same bracketry issues as sntrym had .
I did a EGR delete and used JBA stainless short headers (I had a cracked stock manifold so had to do something and this seemed wiser than finding a new stock one)
Mine is a NV4500 and NP241 4x4 and had no problems with the stock hyd. clutch / bell housing flywheel etc.

Ends up looking like....


I've had big issues finding a decent tune (have around 50k miles on it now) and on the 5th chip. Pulls my 9000 pound race trailer MUCH better than the wimpy stock LO5 190HP 5.7. for sure,, but still isn't 1/10th the toter of a pig block or diesel. But empty it's a BLAST to drive.