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Welcome to the Budget Vortec project.

Goal for this project is to make a nice well performing replacement option for our TBI vehicles without breaking the budget.  I am going to use a used bone stock 255hp Vortec motor and with a nice cat-back system and some TBI mods and well tuned chip, make 270hp (230hp at the rear wheels given 15% driveline loss with 5spd 4x4 drivetrain) and still run on 87 octane gas and get as much gas mileage as I can pull out of it without sacrificing too much power.

1.  Starting off with a used Vortec motor that I am buying through a search of www.car-part.com and I found one for $600 shipped to me.

2.  I am going to use a Edelbrock 7116 RPM series intake this time and I ordered it through Jegs part number 350-7116 for $176.  This intake is a carbureted intake and has no provision for EGR. I will eliminate the EGR in the chip as I can easily get my vehicles through inspection without it.  If you need to have the EGR valve to pass emissions then you must purchase the GMPP TBI vortec intake part number 12496821 $310 from www.sdpc2000.com . I also ordered a Holley TBI to square bore adapter for $48 part number 510-17-45 and gaskets 375-1255 $20.

I ended up changing from this setup due to some initial problems that turned out to be the pickup coil in the distributor.  The finished project utilized the crusader marine TBI vortec intake bored to 50mm from www.xtremefi.com   This intake is kind of pricey but does give a nice stock stealth appearance although it does not have EGR capabilities either.  I will be using the Edelbrock 7116 intake in a JEEP project which will be posted very soon.

3. For the TBI unit, I am going to use the stock unit for now with 350 injectors at stock fuel pressure settings.  I will modify the throttle body as instructed on this page. UltimateMODS.htm to get extra air flow without enlarging the bores and costing me low end torque.  

I found through datalogging that even a modified stock throttle body just isn't enough to feed a vortec motor.  I was still pulling 3 or 4" of vacuum at WOT.  I had www.xtremefi.com bore my throttle body out to 46mm which worked out really well with great low end torque and it revved much higher than I hoped for.

4. The exhaust I am going to keep pretty simple.  I am going to use the stock vortec manifolds that will be on the vortec motor when it arrives and couple them to the stock Y-pipe for now.  I do plan on changing the cat to a 3" CATCO cat $45 shipped on ebay from user JSW1920 and a Summit racing brand mandrel bent catback system for $170  Summit part number SUM-688011.  Trying to keep this project cheap but I would like to pick up some sound quality and a little HP.  I can always add the headers later.

I really don't care for the sound of the Summit racing Cat back system. It does have nice mandrel bent pipe but its too quite.  If you want a nice quite setup then this isn't bad but I much prefer the deep rumble of the dynomax cat back that I have used in the past on these trucks.

5. I am going to put new rod and main bearings (summit part numbers FEM-2555CP FEM-4663M) as well as oil pump in my vortec motor as I feel its a $100 and 2 hrs well spent with the motor out of the vehicle.  

The bearings did appear to have some wear but the crank looked really good.  I used a stock Z28 oil pump which gave me some really nice oil pressure.  Even on a hot motor the oil pump managed a good 50psi which is much better than any TBI motor that I have been in.

6. Since this was a 4.3L truck I will be doing some other modifications which I will post in here as I go.
-- I changed the motors mounts to the V8 mount since the 4.3 is a reverse looking mount I knew it wasn't going to bolt up easily. I reused the clam shell mount that was bolted to the vortec motor that I bought and got the rubber mounts for a 91 4x4 V8 truck as there are apparently 3 different mount possibilities for the V8 trucks so a few trips to the autoparts store may be necessary. I of course had to try all 3.
-- The radiator and shroud. I am just trying this and don't know if I will have an issue or not but the V6 radiator was considerable narrower than the V8 that is in my 96 truck. I will report any cooling issues that I have from using that radiator. On the shroud, I used a jig saw and cut 3" off the end for motor clearance. This makes it pretty close to the accessories but nothing is touching yet. I wanted to totally encompass the fan for more cooling. I used radiator hoses for the V8 trucks and I had to play with them a little to get them on the smaller radiator without kinks.
-- I am still using the stock 4.3 y-pipe which is smaller than the V8 Y-pipe and will be changed in the next phase of this project.

4.3L Radiator has given me absolutely no heating issues and I have run it pretty hard during some of these tests in 95+ heat. The Y-pipe also hasn't performed too badly.  The motor runs STRONG.

7. Little extras are eating me up on this project which is typical of most projects.  I have spend about $300 on odds and ends which others may or may not encounter.  A lot of my issues stem from this truck being a flood vehicle and I have replaced everything electrical in the thing now.

Although, I didn't dyno the motor.  I can tell you the truck runs everybit as well as my 96 Vortec truck and since the motor is a stock vortec motor, I see no reason why this project would not dyno at its goal level since my 96 Vortec truck has the exhaust work and a larger throttle body and performance programming on it as well.

I also drove the truck to its new owner and got a solid 20mpg on the highway with the AC on with it.  Not bad for a 4x4 truck. I can't take credit for all the gas mileage.  It does have underdrive crank pulley and wimpy 3.42 gears with 31.5" tires (265/75R15) which is about 5% larger than the stock 30.5" )245/75R16's that originally came on the truck.  The truck is also a 5spd manual which helps with the gas mileage.  Since the NV3500 has a pretty low first gear the truck would easily burn those big tires through first gear and catch a gnarley 2nd gear patch as well.

Overall, I am very pleased with this project and feel it would make a nice upgrade for any TBI owner.  Check out the Jeep project that is now underway where we are taking the Vortec 350 a little further and giving it a LT1 Z28 cam upgrade as well as 1.6 exhaust valves and a little porting on the exhaust side of the heads as well as done in the vortec porting article on the main TBICHIPS webpage.