Im going to swap out my old 4.3 for a newly rebuilt 350. Its a 350 out of a 94 Silverado 4x4. Im not going to do the tbi application because im going to be camming the **** out of the motor and i dont want to be dealing with re tuning my computer and all that crap. If i put a carb on this 350 and hook up the ignition is it going to run? This is my first GMC build. and hopfully it will be a smooth one. Am i totaly out to lunch or is this possible?

BTW
I live in an appartment and i will be doing the entire motor build in a parking stall in a parkade. I will drive to my buddies place (which requires a ferry ride) for the weekend, put the 350 in and be back to work monday morning.

Is this going to be possible?

 

Yes it is. You will have to take the fuel pump out of the gas tank and just put a strainer on the end of it. You will have to buy an external fuel pump and mount it close to the gas tank. I would put a Holley with a adjustable regulator. Run the pump with a toggle switch on ur dash. If ur camming it out then ur gonna need a higher flow pump. The guages will still all work. I did the exact same thing to my 92 camarao. Took the TBI and intake off, switched out pumps, and she ran good for bout 2 years till i siezed the motor.

 

So on a scale of 1 to 10 how hard did you find it? What about the HEI Ignition, can i just throw on a new coil and boom?

 

The only hard thing was taking out your stock fuel pump out of the tank. I would say a 4 if you drain as much gas out of it as you can. Just use a rubber fuel line and a strainer to sit at the bottom of the tank. After that, everything else is easy. Sure you can put an HEI ignition. Thats what I put with MSD. I used a 650 CFM carb. cuz around here the air is a little thin. High rise edelbrock intake square bore with a spacer. Gained more low end torque by switching to carb.

 

Stupid question i know, but still curious... Am i going to have to change the stock torque converter to get the super lumpy cam idle?

 

Yes cuz it will take more throttle with a bigger cam. A stock torque converter will have about 1500 stall. With a hot cam you will wanna stall it out about 3000. Putting a bigger cam will give you more power but only in the power band. That power band may not start till 3200 RPM's. Plus your power band goes up higher in the RPM range. Lets say your shift points with a stock cam are about 5600. That is where the power will fall off with a stock cam. Putting a hotter cam your shift points will be around 6200.

 

Is their any legal prohibition to changing from the 1990 fuel injection and going to a carb. Truck runs good but when I rebuild the engine, I would love to lose the computer and all that dog-gone wireing and emmission "stuff". Live in Missouri, and have no emmissions test.

 

Only thing you gotta worry bout is gettin an inspection sticker for it every year. As far as being ticketed, no worries. If you can find a hook up it will be cool. Most places are pretty picky on that. They just inspect it visually to see if the emissions are on.

 

Another quick question. I was in at a parts store today and I learned some cool stuff about my motor an cam application in my truck. Along with replacing the torque converter for a lumpy cam, the guy said that i would have to change the gears in the truck too??? Big freaking job considering its a 4x4. It also says on the CompCam website that for the Extreme4x4 Cam i need o have 3.98 - 4.10 gears. Does this have anything to do with the cam giving me a lumpy idle, or the power band of the cam??? Why do i need to replace the gears, and is there any way to get around it. All i want is a wicked idle!!!!! How hard can that be?????

 

You might have too cuz if Im not mistaken you have 2.78's?? 3.42's or 3.73's would be sufficient. See when you install a higher stall torque converter, it means that it slips more and creates more heat, which is number 1 killer in transmissions, heat. When you cruise it will stay in the gears longer and will slip more till the RPM's go higher and then will grab. So longer gears will create more heat and your torque converter wont last that long. Think of driving a standard and trying to take off hard but your tires grab good. You can feel the clutch slipping on the flywheel but its trying to grab and eventually will at a certain temp. Like rubbing your hands together and feel it heat up and grab. Kinda the same thing. Except the converter will grab at a certain RPM. The torque converter is a housing for clutches. The dealers put lower stall converters for longevity. Getting the right set up will virtually guarantee how long your parts will last. In the end, it all depends on maintainance and the love for your ride.