The Stovebolt Site Forums The Shop Area The Electrical Bay Need diagram for 350 TBI harness mods

I'm installing a 350 TBI sbc from a 1993 Suburban into my 56 Chevy 3600. I have the stock complete harness from donor engine compartment and under dash including the fuse block and ECM. The donor truck had all the bells and whistles so I need to know what the bare minimum connections i need from the stock harness to keep the TBI running well. Ive searched some old threads but the links no longer work. I sure would appreciate some help so I'm not reinventing the wheel! thanks

Snowman? Are you also installing the tranny that came behind that 350 TBI engine? It would be either a 4L60E or a 4L80E (electrically shifted). If “yes” then your installation is feasible. If “no” then your installation becomes electronically much more complicated, if not impossible. Also, the Vehicle Anti Theft System (VATS) from that Suburban directly interfaces with the ECM, such that the computer won’t power your fuel pump circuit if it doesn’t get inputs from the VATS. There are guys out there in cyberspace that have the smarts to defeat missing inputs or outputs from things like the auto trans or the anti-theft system by reprogramming your computer: $$$$$. If you have an automotive background that includes working intimately with OBD-1, then you might have a chance of making your idea fly on that 3600. (Been there, done that, but wouldn’t do it again). If you’re just a weekend warrior, well, you might save yourself a lot of aggravation and do like bartomos suggested, and go w a carburetor and HEI.
Good luck.
Dave

Flatblu4748

I was planning on mating a 700r4 to it. If I can power the fuel pump directly from the key RUN and START positions, will this work?

what intake and carb would you recommend? thx

Snowman, your last post makes it sound like you’re not going with the TBI idea on that 350. I’d be reluctant to recommend a carb or intake alternative as there are so many variables. Maybe do do some research? Depends on what you’re after: performance, driveability, fuel economy, simplicity? And how deep are your pockets. Also, you mention you’re “planning on mating a 700r4 to it”. Be aware that sometime around 1988 that GM began phasing out speedo cables in favor of electronic vehicle speed sensors (VSS). I’m guessing you’d like your speedometer to work on your 3600. You’ll want a 700R4 that has the cable feature; and then you’ll have to have the correct drive and driven gear at the tail shaft to accommodate your axle ratio and tire size. All doable, if you know what you’re doing, or if you know someone you can lean on and learn from, who can walk you thru all the details. There are plenty of good reasons that the purists among us keep ‘em stock; then there are guys like you and I who endeavor to go the street rod direction, for whatever reason.....and re-invent the wheel, and that opens up another can-of-worms....
Good luck,
Dave

I want to make this a daily driver only with the best mpg feasible given a carb...and yes I've given up on the original TBI based on your comments regarding the difficulties associated with keeping the original TBI in my 3600.

You might pick up a copy of April 2019 “Street Rodder” magazine. There is a tech article on using carbs with the 4160 tranny. End of article has sources which may be helpful to you.