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1project2many · 10-02-2014, 06:53 AM

6 cyl TBI conversions are relatively straightforward. The devil's in the details, of course. The way the OP modified the distributor is acceptable, the 4.3 TB is appropriately sized, and the heated O2 helps but shouldn't be needed. I'm not sure why the OP decided the stock ecm wouldn't work, there are plenty of EFI retrofits using early car or truck ecm's. The issue boils down to tuning... adjusting the parameters in the chip so the stock ecm works properly with a different size engine with some very different characteristics than the engine it was originally programmed for. As I read this post it seems like the OP followed a path that many others do: Retrofit efi with stock ecm and programming, try different combinations of stock parts to try and obtain acceptable performance from stock programming, come to grips with need to tune. If you're doing an EFI swap on a vintage engine consider tuning an essential part of the job.

If you start a thread asking for experiences or talking about what you want you might get additional input from those (including myself) who have had success.

10-02-2014, 06:53 AM	#55
1project2many Registered User Join Date: Mar 2012 Location: Lakes Region NH Posts: 3,158	Re: 235 inline 6 running of fuel injection 6 cyl TBI conversions are relatively straightforward. The devil's in the details, of course. The way the OP modified the distributor is acceptable, the 4.3 TB is appropriately sized, and the heated O2 helps but shouldn't be needed. I'm not sure why the OP decided the stock ecm wouldn't work, there are plenty of EFI retrofits using early car or truck ecm's. The issue boils down to tuning... adjusting the parameters in the chip so the stock ecm works properly with a different size engine with some very different characteristics than the engine it was originally programmed for. As I read this post it seems like the OP followed a path that many others do: Retrofit efi with stock ecm and programming, try different combinations of stock parts to try and obtain acceptable performance from stock programming, come to grips with need to tune. If you're doing an EFI swap on a vintage engine consider tuning an essential part of the job. If you start a thread asking for experiences or talking about what you want you might get additional input from those (including myself) who have had success.