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350 TBI to 383 with Flo Pro Swap

MT Bill

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Hello,

First time DIY engine swap for this guy so any tips and advice are welcome as I will probably have plenty of questions and dumb ideas.

My 1990 GMC V1500 Suburban with a 350 and 700R4 lost its 350 TBI motor this summer. I have always wanted a 383 stroker, so I figured now or never. My other thread (https://ck5.com/forums/threads/90-burb-getting-a-383-which-fuel-system.341274/) and other threads on the topic led me to decide on ditching the TBI setup for an edelbrock flo pro 4. This was stretching my budget a bit (ok alot), but I convinced my wife (and myself) that we would be better off investing some money in my old suburban rather than going out and getting a new vehicle payment. We have to have 2 rigs and prefer to keep a 3rd running as a spare. Our spare has been my full time since August and I'm about done with the car!

I ordered the 383 from S&J engines out of Spokane, WA. The flo pro 4 with volcano (and other various parts) were ordered from @folkenheath.

20201023_173527.jpg
20201108_125831.jpg
20201027_174930.jpg


The weekend I planned on pulling the motor this happened . . .
20201024_102701.jpg

and my garage isn't big enough to fit the suburban and use the engine hoist. So after another 14" of snow fell later that week, it thawed and warmed so I got started pulling the engine two weekends ago.

Out with the old . . . 20201030_105441.jpg 20201031_141026.jpg

A week ago Sunday I installed the new in tank fuel pump and started to prep the new engine for install. Installed the new intake manifold, went to torque the bolts and broke the second one off! WTF . . . well I had set the torque wrench to the wrong line and was getting over 30lb/ft rather than the 11lb/ft called for. Couldn't find my ez-outs so off to the parts store in the morning. Luckily it came out easy as pie.

Here's where the novice shows through! I didn't quite understand what I was getting and what all I was missing at this point. I like to do my own work and enjoy wrenching on my own stuff, but I have never done an engine swap so some may find my complete mess of planning/execution amusing. If nothing else this has been a learning experience so far and will continue to be as I get this finished!

1. Timing cover/gaskets: none on new engine. Needed buy gaskets and remove old cover. After getting prices locally I decided to order a new one from summit with gaskets. Also ordered new stainless bolts.

2. Oil pan/gasket: no pan on new engine, but they did supply the gasket. Ordered new bolts from summit.

3. Oil pump: came with engine, but no pickup/screen. I ordered the wrong size screen . . .

4. Rear main seal: supplied in gasket kit with engine, but no retainer. Remove from old engine and cleanup

5. Valve covers: none supplied with new engine. Old ones were caked with sludge and did not want to come
clean . . . order new ones. Then realized I'll need breathers/caps/PCV

6. Headers: Ordered new shorty headers hoping to use old exhaust.

7. Serpentine accessory drive: I planned to use all the old stuff

8. Radiator: TBD still, but will flush and use the old one temporarily (same with water pump).

9. Oil cooler: Deleted and a Melling oil filter adapter ordered.

Thursday after work I started prepping the new engine for install. . . . this is when I discovered the supplied melling oil pump required a 3/4" pickup tube/screen and I had ordered a 5/8".
image-20201105_211002.jpg
So Friday (day off work) I drop kids off at school then my daughter and I drive the 40 minutes to the next closest O'Reilly's with the correct size in stock. I get home and go to install this thing and wow . . . without the correct tool that is a pain in the * to install. I set the angle for pan clearance then drilled and tapped the pump to install a set screw. Set screw received green locktite and then got pined in place with a few punches from a chisel to make sure it never walks out.
20201106_125821.jpg

Pump installed, rear main installed, oil pan with new bolts installed, flex plate installed . . .making progress!

I installed the new flo pro manifold the prior weekend, but then realized I forgot to put RTV on the front and rear portions where it mates to the block. Drop the engine from hoist, remove manifold, apply RTV, reinstall manifold.
Install timing cover with old bolts I painstakingly cleaned and painted the night before. Install balancer, then realize I forgot to install timing cover with the new stainless bolts I ordered. Oh well, too late now. I was glad to see that when I installed the timing indicator tab it lined up perfectly with the timing line on the balancer! Win

Test fit headers and valve covers and take a pic.
20201106_162514.jpg

Installed new poly motor mount bushings in the old clamshell, clean and paint the old motor mount hardware for the engine side.
Adjust the valves, rotate engine, adjust valves, rotate engine, adjust valves again. Install baffles in valve covers, break off screw in valve cover! Decide that will be the side to fill oil with. Install the other baffle and use better screws. Nothing broke this time. Install valve covers. Install motor mounts.

About ready to drop in the engine, then I look at the old wiring. I figure I'll need the oil pressure sensor, coolant temp sensor, and alternator wires for gauges to work. I'll need the coil wire for new coil. And the rest I hope is ready to be cut off, but I get nervous about hacking on the old wiring and tape it all up and stuff it out of the way for now.

Dropping the engine in . . . . well that was fun! Took about 2.5hrs longer than I had figured. The drivers side did not want to slide down over the motor mount. A little persuasion with prybars, hammers, and finally 2in ratchet strap around the motor mount-under the front axle-back to the transfer case cross member made her slide in to place.

Yesterday I finished bolting up the transmission and torque converter. Installed headers and connected exhaust (they fit!). Installed fuel lines and fittings; and started installing the serpentine/front accessories.

20201108_162646.jpg

With any luck during my evenings after work this week I'll be able to install the flo pro wiring, starter, finish front serpentine drive, and reinstall the radiator/hoses. . .
 
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MT Bill

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So questions for the experts:

For those of you that have installed a flow pro 4 system on an old TBI motor:
- What wires did you keep? What wires did you remove? How did you go about cleaning up the old wiring?
If I install aftermarket gauges at some point can all the old wiring go away?

- Has anyone installed with a 700R4? If so how did you control lockup?

- Any options for cruise control? It hasn't worked in the 5 years I've had the rig, but it would be nice for those multi hour insterstate drives.

- Am I missing anything else?
 

folkenheath

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Looks great so far! I bet you are excited with that new setup.

I like how you pointed the injectors inward to keep the wiring tidy. I look forward to seeing it running!
 

mrk5

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If you do some searching, you should be able to find wiring diagrams for your truck online that you can download. I have PDF versions of 1989 stuff. That's what I used to trace out wiring to use for the aftermarket EFI as well as what I could get rid off.
 

mrk5

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I forgot to add, my 89 came as a 2wd with SM465 manual. I put a 700r4 in with the 4wd conversion and I had the lockup on a switch in the cab. TCI also make an add-on piece that will use a vacuum signal to lock up the torque converter. I didn't really care for the way it operated, which is why I just used the switch.
 

6872xtc

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So questions for the experts:

For those of you that have installed a flow pro 4 system on an old TBI motor:
- What wires did you keep? What wires did you remove? How did you go about cleaning up the old wiring?
If I install aftermarket gauges at some point can all the old wiring go away?

- Has anyone installed with a 700R4? If so how did you control lockup?

- Any options for cruise control? It hasn't worked in the 5 years I've had the rig, but it would be nice for those multi hour insterstate drives.

- Am I missing anything else?

I'm no expert, but I will try to help.
:D

I can't tell you exactly what wires I kept, I spent some time looking at my schematic and just old school tracing wires.
I do remember finding a couple of wires that went through the firewall with the factory TBI harness that I needed. I am believe that one was a ground for speedometer. Not positive if the other one was signal wire for the alternator or what. Too many years...

My 700R4 appears to have been modified for fully hydraulic lock-up. I have used a switch on 2 of my old trucks. There may be a better option, but I haven't tried any kits.

I haven't messed with my cruise control yet because I haven't found a way to attach the stud to the throttle lever so that it clears the side of the throttle body.

I will try help more later, I already am watching your other thread. Good progress!
 

MT Bill

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I'll update after the weekend:

- Installed the rest of the front accessory/serpentine drive. Re-installed PS pump, alternator, tensioner, idler. Installed new water pump.
- Figured out and installed the throttle & kickdown linkage/bracket. Ended up using spacers to lift the throttle cable and mounted the kickdown cable underneath the bracket on the inside of the throttle body lever. (Will get pics of this setup soon)
- Had to install a air cleaner spacer to clear the throttle cable linkage spacers added above
- Installed radiator, coolant hoses, heater hoses
- Installed vacuum lines for brake booster, PCV, & fuel pressure regulator
- Installed new fuel filter
- Installed new coil (with a proper coil mount)
- Installed the Pro Flo wiring harness and all sensors. Tried to run the Pro-Flo injector wiring underneath the intake runners and got frustrated getting the plugs stuck and gave up after an hour. So the injectors got pointed inwards and the wiring run on the inside/top next to the fuel rails.
- Connected the Flo Pro fuel pump wires to the OEM fuel pump relay after finding some diagrams online. Actually got those wires correctly on the first try.
- Primed the engine with oil
- Installed the distributor and set timing to 12 deg BTDC
- Connected all the plug wires (and actually got them in the right order!)
- Reinstalled old starter and another newbie move here . . . see below

After all above work I was ready to start her up on Sunday mid morning . . . . turned ignition on . . . the fuel pump doesn't kick on. Well what the heck? Oh, I forgot to plug it in! Now time to start: turn the ignition on, fuel pump kicks on, took a while to figure out the PIN for the ECM bluetooth, started the setup wizard . . . time to start the engine . . . turn the key . . . nothing! hahahaha

So I start checking wiring: positive connection on battery, check. Negative connection on battery, check. I did find some factory grounds in the wires I taped up, so I pulled them out and bolted them to the back of the passenger side head.

Try to start again . . . nothing

Then I think well maybe my starter went tits up. So I pull the starter and bench test it . . . nothing. Time to run to town. So I go down to town, Napa is closed on Sunday and O'reilly's doesn't have the exact on that fits so I get one for a newer 350 to try. Go home and then remember there are 3 connection posts on the starter, a large post for the positive battery cable, and two small ones-one for the ignition, the other ??

So I bench test the old one again using both of the small posts and I'll be damned if I wasn't just using the wrong ignition post before.

So I reinstall the old starter and try to start it again . . . nothing

OK, maybe my grounds aren't good. So I remove, clean, and re-install the grounds to the block and frame. Try to start again . . . . nothing . . . .:doah: My wife has left the garage hours ago and returns to tell me to call my brother for help! Seriously! I'm pretty adamant about figuring out things for myself, especially when I know its not over my head.

Then the light clicks in my brain and I realize I connected the ignition wire to the wrong damn post on the starter again!

Time to start again . . . connect to the pro flo ecm, run the setup wizard for the 4th time . . . prepare to start engine . . . turn the key . . .and it starts! YEAH! Finally!
That moment felt pretty awesome!

I got the base timing set and now its time to take the engine out for proper break in. But at this point its almost 6pm on Sunday and with my getup for work time being at 3:30 am I call it a day.

Next I just need to install the grille and hood and take it out for a spin! Can't wait . . . .


(photos to come)
 
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mrk5

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I had to raise my air cleaner for the throttle linkage as well. I bought a different base for mine.
 

MT Bill

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I'm trying to decide whether I just want to run a spacer, find a different base like you did, or switch to a velocity stack type setup.

Mind sharing which base you used?
 

sweetk30

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stock air cleaner on mine with storkle tube to core support . then a old school hypertech air filter base kit that opens up the flow and you cut open the air filter base to match it .

old pic with SH!TTY SNIPER but you get the point on the spacer and air cleaner base . fit the same no problems on pro flo 4

1021181652a-jpg.282595
 

6872xtc

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I did a variation of the salad bowl trick with my stock '90 housing. I found an air horn adapter with some help from @Bent77 . Just used some rope style sealer tape where it meets the trimmed factory housing. This let me use the factory cold air tube to the radiator support. I want to make it a dual snorkel someday.
 

folkenheath

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My suggestion is to keep the air cleaner the large 14" diameter by just getting the different base, this gives you more leeway for it to be a little dirty and still have plenty of airflow vs a smaller air cleaner.
 

6872xtc

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My suggestion is to keep the air cleaner the large 14" diameter by just getting the different base, this gives you more leeway for it to be a little dirty and still have plenty of airflow vs a smaller air cleaner.
While I see your point, what about pulling hot under hood air? Having the intake air temperature sensor is nice, IMO.
 

mrk5

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While I see your point, what about pulling hot under hood air? Having the intake air temperature sensor is nice, IMO.
They did an interesting test on Engine Masters about intake air temperature and the figured out the fuel temperature made more difference than air temperature. If I remember correctly, the air temperature made no difference.
 

folkenheath

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While I see your point, what about pulling hot under hood air? Having the intake air temperature sensor is nice, IMO.

By the time the air actually gets into the combustion chamber it's pretty hot either way, then it gets compressed and gets real hot before its ignited. I think this cold air makes a much larger difference when you have forced induction.

However, there are companies that make plastic shrouds you can sandwich in the 14" air cleaner and hook an intake hose too if you refer to do both. Just be careful, you can end up creating more restriction and that is worse than hot air. I don't have a problem with that, cold air is good, but more air is usually better. I've seen people pick up 2 tenths and 2 MPH (about 20 hp at his level) just by removing the cold air piping because it was restricting the actual air intake at RPM and Speed. Not saying that will always be the case, I'm just saying if you do add it, keep it full flow.
 
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