'74 K5 build: Smurf

[Greg72]

I came here for the speedholes..... And left disappointed!

Nice work brother. I turn my back for a short 10 years, and next thing I know you are laying down some pretty respectable beads all by yourself!


-G

 

[dremu]

I came here for the speedholes..... And left disappointed!

Nice work brother. I turn my back for a short 10 years, and next thing I know you are laying down some pretty respectable beads all by yourself!


-G

Three S's, not four. Speed just isn't Tankie's thing

And thanks! I blame (err, credit!) CK5, you included, for enabling (err, encouraging) me

-- A

 

[skunked]

nice use of the wing nuts

I was debating using a lock on the studs like you did but I should probably just do it.

 

[dremu]

nice use of the wing nuts

I was debating using a lock on the studs like you did but I should probably just do it.

Yeah, I figger it keeps the idle sticky fingers from borrowing stuff. Hi-Lifts are popular enough, and costly enough, that I don't want mine developing feet. I think if you had a hard top and locking doors it wouldn't be a big deal, but I have a soft-top which means the doors are anti-lock

-- A

 

[skunked]

Yeah, I figger it keeps the idle sticky fingers from borrowing stuff. Hi-Lifts are popular enough, and costly enough, that I don't want mine developing feet. I think if you had a hard top and locking doors it wouldn't be a big deal, but I have a soft-top which means the doors are anti-lock

-- A

mine will be on the bedside so it's out in the "open" for those sticky fingers.

 

[dremu]

mine will be on the bedside so it's out in the "open" for those sticky fingers.

Oh yeah, I keep forgetting you're one of the communist types with a pickemup.

-- A

 

[dremu]

The Continuum Transfunctioner is a mysterious and powerful device whose mystery is only exceeded by its power. For many years I swore I'd never have transistors of any kind on my truck.

Then I got tired of points and put on an HEI distributor. Mysteriously, it ran better, more reliably, and didn't need adjustment every ten miles For more years I swore I'd keep the Quadrajet as it's a perfectly good carb and it worked. If by "worked" I meant it wouldn't start right off in the cold, had to bang on the gas pedal several times to get it going. And if it hadn't been started in a few days, I had to wave a dead chicken around and chant in Latin to get the damn thing to go. Etc etc.

So I saw this thread and read up on TBI conversions and Howell particularly, and pulled the trigger.

First up, I'll say yes, they're expensive. You can spend a lot less and use junkyard components vs the kit coming with all brand new, GM parts. It also comes with a brand new wiring harness and ECU custom configured to your truck. This particular kit came with the dizzy and an adapter for the manifold from the carb to the TBI. My particular truck is smog exempt, so I had a few challenges blocking off the EGR and choke and whathaveyou on my carb intake.

But first, the regulatory pix... namely, the air cleaner removed and the carb and its vacuum hoses and such:

 

[dremu]

And then the carb is removed and the harness is strung, new dizzy in place, etc.

Note the block off plates for the EGR and choke. These are generic Edelbrock parts from the speedshop, BUT they added enough height that the TBI wouldn't clear them. The solution was a 1" carb spacer under the TBI adapter, which was a bit kludgy, but with the appropriate gaskets and careful torque has stayed sealed without vacuum leaks.

You can kinda see the spacer under the TBI adapter. The spacer is a cast aluminum thing, that being what the speed shop had, and the adapter is a machined piece of solid aluminum. I've been very pleased with the Howell product; they obviously understand the system and how to work with it.

The instructions were a bit circuitous, so you REALLY have to read through the whole thing several times, and then decide for yourself in what order you'll do things for your particular truck. Their paperwork is kinda generic, as they do TBI setups for basically anything (non-GM's, 4- and 6- cylinder, etc.)

In my case, I welded the bung for O2 sensor (all included in the kit) into the exhaust:

and plugged it, as shown, driving it for a bit to make sure it didn't leak. I reaally hate exhaust work, got rust and panther piss all over the driveway.

 

[dremu]

Then Tankie went into the Cone Of Shame for the major work to be done (rainy season, much easier to work when dry.)

The first order of business, before the underhood work above, was replumbing the fuel system. TBI has a return line from the regulator to the fuel tank, and my truck did not.

The mechanical fuel pump also had to go:

and was replaced with an electric one (included in the kit) along the frame rail:

My particular truck had a convenient junction between sections of hardline where I could loop in the pump, albeit facing backwards. There's also an inline filter that came with the kit. Again, the Howell kit is spendy, but they included damn near everything I needed. Weatherpack connections, hoseclamps, a length of return hose, etc etc etc.

Yes, it's temporarily zip-tied there until I clean it up later.

Finally, I dropped the tank, one of my least favorite activities, and switched out the sending unit to a newer style with the appropriate number of ports:

My charcoal canister was all gummed up and in the way of the auxiliary battery, so I decided to get a new one with the appropriate ports and plumb it in while redoing the fuel hoses:

That's the passenger side inner fender.

 

[82355]

Nice.

Martin

 

[dremu]

I did have to make the mounting for the ECU, just some aluminum angle:

and self-tapping-screwed it up high under the dash, behind the glove box. The ECU fuses are up there too, and the ALDL connector is zip-tied by the under-dash light.

Also, Howell leaves up to you the mounting of the various modules and such (ESC, the coil, etc.) Since my carb intake is very similar to a TBI intake, a Pick-N-Pull run netted me a set of factory brackets which fit with minimal modification.

Anything painted Rustoleum Dark Machine Gray is added parts That blue crankcase filter was temporary until the snorkel was set up, at which point the vent was filtered inside the snorkel plumbing with a factory style filter.

The throttle bracket dropped right on and I was able to use a throttle cable off a TBI truck. The kickdown cable was a bit trickier, as TH350's either didn't come on TBI trucks or were rare enough I couldn't find a listing for one, so I found a generic adjustable kickdown cable. Eagle-eyed viewers will notice it's not connected in the pic above.

After quadruple-checking all the hoseclamps and electrical connections, I turned the key and was treated to the (click) of the fuel pump relay for the proscribed two seconds, and then turned the key.

It started right up. Just like that.

Now, those of you with TBI trucks won't get this, but if you've ever had a carbed truck, you'll understand that this is powerful magic indeed. We had a coupla really-cold-for-California nights, down to ~30F, and same thing. Go out, turn the key, let it prime, crank. And she'd start right up. And now in the summer, if you want the truck to go, all you gotta do is turn the key.

No banging on the gas pedal. No waving of dead chickens. Sooo much less wear and tear on the starter and battery .... mystery and power indeed!

-- A

 

[dremu]

Finally, the TBI was plumbed to the snorkel. (Though the snorkel appears earlier in this thread, it actually occurred after the TBI conversion.)

The intake plenum and filter are Spectre brand, your basic ricer stuff. O'Reilly's and Vatozone can order them if they don't stock them. I did have to juggle the 4" down a bit to fit onto the snorkel, see the blue adapter at the outside, but it basically all fit onto the factory ducting (black plastic.)

And yes, I changed out those hose clamps to real T-clamps later (see the clamps between the plenum and filter, vs the ones on the black plastic); I had to order the other size. [There's a lengthy thread, or three, here about how the regular hose clamps can come undone at inopportune times, leaving a big metal filter canister loose in the engine compartment. ]

-- A

 

[dremu]

Nice.

Martin

Yeah, hands down, this is The Best Mod Ever for this truck. If I'd known it was this simple I'd have done it aeons ago. Carbs may have their place on the track or hot rods or something, but for normal street vehicles, nope, no way. EFI just fricken works.

And yes, I know I could have trouble with a sensor or wiring or whatever down the line. Because Howell used GM parts and GM wire colors and such, fixing it will be just like fixing a factory TBI truck. And I'd honestly rather work with an electrical/sensor issue than a mechanical or vacuum problem in a carb.

-- A

 

[Greg72]

Dead chickens indeed...!

Nice work buddy!


-G

 

[tRustyK5]

bye bye '70's...hello 80's!

Have you heard of this other new thing, called FM radio? It's sorta like AM, but more better.

Being serious, nice swap...FI is a damn sight better than carbs. Anything that just makes a vehicle work better, smoother etc is a great mod.

 

[bp71k5]

Do you have any tuning to do after driving it for a while?

 

[dremu]

Do you have any tuning to do after driving it for a while?

Howell asked for details on the motor when I ordered the kit, they send an ECU custom-tuned for each situation. In my case it's a bone stock Goodwrench 350 crate, likely the same as the stock TBI-era motors (except maybe the cam is different for carb, I donno.) Anyway, she runs just fine, as well as she ever did with the carb, so I don't feel the need to fiddle with it.

-- A

 

[beags86]

What's next? Overdrive trans?

 

[dremu]

What's next? Overdrive trans?

I have considered a 700R4, yeah, but I think it'd mean changing drivelines and moving the shifters and crossmembers and everything. Unless there's a way to make a 700R4 the same length as a TH350, in which case it'd be easier.

-- A

 

[dremu]

*($&@*($@ Rockauto. They post in the Vendor forum here and you find fun things, like I need more projects! [And yeah, I'm a bit behind on updating this thread, but life happens, you know?]

Specifically, it was a rearview mirror:

that LOOKS like a perfectly ordinary mirror, but magically also has wiring

for a video connection for a backup camera:

There's a little LCD monitor in the left half, like 3.2" or something. Note it's hard as hell to take a photo of an image inside a mirror.

The camera has a bracket that mounts to the license plate in the back, and I can now see the nuns, hopefully before I hit 'em.

In fact, the mirror has TWO video connections. The backup one comes on automatically when put in reverse, but I also wired up a switch and a cheapo Chinese front camera:

hard to see as it's literally like an inch cube, but it's above the winch on the bar holding the lights. Right now it's just zip-tied in place until I decide I like the position.

The main camera kit was two hundred and something, not exactly cheap, but it came with the mirror unit and the rear camera and all the hardware and wire (long enough even for a big-ass truck.) The front camera I got on Fleabay for like $20, so overall not stupid money. One interesting thing I discovered is that backup cameras have to flip the image left-to-right, so they display properly when you're looking forward. It's *harder*, weirdly enough, to find a camera that *doesn't* do this for front use. Another peculiar thing is that the red-yellow-green guidelines are generated by the camera, and not the monitor. The "backup" cameras typically have this feature (but it can be disabled by cutting a wire), and the "front view" ones typically don't.

Wiring it up was easy peasy, like doing trailer wiring or car stereo or whatever. The mirror basically takes power and ground, as do the cameras. The power for the backup goes right to the reverse circuit, and the front one just goes through a toggle on the dash when I want to see the forward view.

-- A