ajr3268@gmail.com

So I got a 1994 chevy Silverado stepside, it’s a 4x4 model. The original motor was a 350 tbi, previous owner had a water leak somewhere and let it run with no water and the block warped and a cylinder head cracked. I went ahead and picked up a motor on Facebook it came out of an unknown Cadillac car and it’s also a 350 tbi, I got the motor in the truck fit perfect but I have a couple questions that I’m hoping somebody can answer for me !!
Thanks for the answers ahead of time guys sorry I am new to the Chevy game, was a ford guy before :/.
1. The water pump on the new motor has 3 holes for hoses, the original motor only had 1 that went to the radiator, can I still use this different water pump and why does it have 3 holes instead of the 1?
2. Since the motor is out of a Cadillac, can it still work in the truck with the stock ecu and wiring/sensors?(new motor has a few new sensors that the truck did not have before that I’m gonna have to leave not connected)
3. the tensioner on the newer motor is different then the original motors tensioner, how do I move the tensioner to be able to take off the belt?(the older motor I could just use a crowbar and move the tensioner enough to get the belt off)
4. I just looked more at it, would I be able to just take off the boot that holds where the 3 exit holes of the water pump are at and be able to use the like the older water pump or is it the same water pump this whole time

kevinkpk

First, you have a whole new different animal in there. 1) there where 3 lines from the water pump, one may have been to the heater core, 5/8"? 2) I don't know about the ecu, since you have extra sensors, my advice would be to just hook up what you have, then go from there. 3) The tensioner should be self explanatory, and why do you need to change it? It is for that engine. 4) yes, you can hose terminate the openings from the water pump, however as in 1) you might be stopping flow to the heater core. You have to think that what is on this engine is for that engine, and the caddy it set in.

kevinkpk

If the water pump is interchangeable with your new block, I'd suggest that, and reconnect to your truck.

Little Bear

I'd say pull off that short hose and get rid of the 3 outlet thing and hook it up the bottom hose directly to the pump. The tensioner, 15mm socket on the bolt in the center of the pulley, twist clockwise to remove the tension, the whole pulley should pivot. Hook up the sensors that you can and see how things go, I don't think you will have a problem.

kevinkpk

The one thing with the 3/4 or 5/8 outlet, is it might feed the heater, otherwise, yep.

Little Bear

Heater core is fed from the outlet next to the top radiator hose on the engine, you can see it in the photo, the outlet of the core goes directly to the radiator right below the cap.

ajr3268@gmail.com

hello again guys sorry for being late I decided to work on the truck on a later date due to all the rain over here in Florida , I took the little adapter plate with the 3 hoses on it off and yeah looks like a hose can matte right up to the water pump like it originally was, the bracket that came off with the 3 hose exits had a thermostat in it so I’m hoping the motor has a second thermostat in the original location like the old motor. The above pictures are new motor compared to the old motor, the old motor had the same spot for the bracket that had the 3 hose exits the same bolt holes but the new motor under where the bracket went has oil passages behind it. The bracket that went on it to cover it didn’t run any oil it’s just a plate that blocks the oil from coming out, why does it have these holes there? The 2 pictures above compare the 2 different engines where the bracket matted at. Could I use the bracket plate and cut it so it does not hold the 3 hose exits anymore and just use the base plate from it to cover that hole since it looks like the oil didn’t run anywhere once in through the passage ?
Thanks again guys and again sorry for replying late , thanks for all the answers I very much appreciate !!!

Little Bear

There was a change over time when going to TBI that the blocks still had the mounting for a mechanical fuel pump as you are seeing with your new engine. Here's an easy fix, https://smile.amazon.com/Mounting-Ch...s%2C373&sr=8-2

You can probably pick one up at a parts store.