TBI Conversion

**KeyAir** · 01-29-2021

Hi Everyone!
I have a 1973 Chevy K10 Pickup with 350/350/NP205, that I'm restoring/converting into a Wilderness camper.

The original Quadrajet was giving me problems for years and a rebuild by an "Expert", made things worse.
I swapped on an Edelbrock, and that was its own nightmare.

Anyway, I have had TBI's on BBC's before and loved the way they ran and the reliability, so I thought a 350TBI or a MSD Atomic would make sense.
Reliability and parts availability would be a priority...
The Motor is a 350 4 bolt... maybe the the original, but was rebuilt sometime... Compression showed 160psi ish across all 8, so OK.

So, this week I picked up a used TBI, but I think mostly complete setup... for $150.... saved me spending a week at the Pick and Pull at least!
Its from a 350, so smaller bore unit, Intake manifold, ECU and harness, Dizzy, 2 coils, EGR, Fuel pump relay, and a bunch of parts that I recognize but need to verify what they are.

First surprise was the Intake... Its Aluminum, not cast Iron as the BBC units are... Is that normal?
I was planning to run a Edelbrock Performer Intake that I have on hand, with an adapter..
Is this stock intake good?
The ECU is stickered Service No. 16146299 AWLD.
My research here says its a 1992 305/350 ECU.

Any advice, input or comment to help me is welcome!

**trlrider** · 01-29-2021

To use the TBI intake on you SBC you will not to slightly ream out the middle bolt holes. They have a different angle then the ones on the end. I use old rocker balls and a slightly longer bolt. The rocker ball will self align to the intake for even pressure.

But using the Edelbock or any similar dual plane intake works as well with the TBI adapter.

Sounds like you pretty much rounded up everything! Did not see a O2 Sensor listed, you will need one, usually on the left exhaust pipe. If you are running stock manifolds, on the pipe about 2 inches from the flange. If you are running headers you will want a 3 wire heated O2 sensor, as the collectors are to far away from the head and you will have tuning issues.

I am pretty much doing the same thing. Swapping my nearly near 350SBC from my wrecked 1986 Blazer into my 1993 Suburban utilizing a adapter plate. Only real difference is a Gen1 motor going into a already TBI equipped truck.

**KeyAir** · 01-29-2021

Thanks for the input!
I did not see an O2 but, I have headers with dual exhaust and no H pipe, so 3 wire it will be.
Actually I have a pair of "727" ECM's to hand from from an "87 and '90 R20 454 suburban, and just read they are better supported and maybe work in this application?

**tayto** · 01-29-2021

I think you mean 747.727s were an underhood ECM on the TPI corvettes. As for intake, I would just run an adapter plate. GM actually used one on the 454 TBIs that still had a Qjet manifold. You can find them on ebay, kinda pricey now bit a factory piece nonetheless.

**dave w** · 01-29-2021

Gearhead-efi link for TBI computer 16146299: http://www.gearhead-efi.com/Fuel-Inj...Information-99

dave w

**KeyAir** · 01-29-2021

Thanks.
Yes, 747. I remembered wrong, lol.
Apologies in advance for my lack of knowledge and questions!
So, I have the factory aluminum intake, and an Edelbrock performer.
As its TQ/MPG I’m after in this mild setup what are people’s opinions on one vs the other?
The truck is pre-smog, so I can do what I want without worries here in CA... and it will still be cleaner than the carb.
Have a complete spare 454 TBI system on hand but assumed a small block setup would be better suited.
I built myself a Vapor Blast Cabinet last year, so whatever intake I use will be blasted and Cerakote’d.
Same for the TBI unit when I rebuild it.
Should I bother to to mill/smooth it?
Adjustable FPR?
Injector spacers etc?
Can you rebuild the injectors on these, or should I just replace?
If so, who does them best?
gotta figure out how to post pics here.