1953 GMC w/Chevy 235 convert to TBI

[Lins]

Hey everyone, as per the title I’m looking at converting to TBI with a late 80s 4.3 throttle body. I see lots of good info on here and elsewhere on how to do it. My question is - should I go with a 1227747 ECM for now or jump right to a Speeduino/Megasquirt setup? A stand-alone ECU setup would be new to me but I see it as extremely usable for future performance plans and also a bit more $$$. Has anyone converted a similar engine to provide some pros and cons? I would purchase the kit pieces this summer to get ready to convert over next winter. I have some experience with HPTuners and EFILive and have access to some nice Megasquirt training videos from HP Academy.

Thanks in advance!

[1project2many]

Hello! Welcome to the forum.

There are advantages to using parts that can be found in wrecking yards and in parts catalogs. I would recommend matching the throttle body to the engine power level. A stock 235 does not need the same amount of fuel and air as a stock 4.3. A better match might be to use a 2.8 TBI unit. 7747 is a good ecm choice and they can still be found reasonable inexpensively. I used one in my '57 truck for years before moving to a later pcm. Are you going to buy tools to read and write chips?

[Lins]

Thanks I’ll keep the smaller throttle body in mind - on another forum I’ve heard mixed reviews about if they flow enough. Yes I would look into possibly getting the tools I would need for the GM ECM. I have a few for OBD 2 vehicles.