early 4l80e to 6.0?

[joe yuhaus]

there we go never thought of asking the guys who have done a Cummins swap how they did it. makes sense though if it would just be TPS and the speed sensor. And and es that' my plan I don't want to remove any of the tbi wiring or electrical really I used the stock stuff for my fuel system. I'm putting the motor in next weekend will try tying into the ls TPS and see what happens. thanks for the tip, and I agree the newer trans would be nicer but just a few months ago I had this one rebuilt and beefed up intending to make more power down the road.

 

[joe yuhaus]

I never intended to do an ls swap to this truck at all but the TBI system started acting up and I figured if I was gonna get rid of the TBI anyways why carb a newer truck. so I want to build the 350 and put it in the 86. And with how simple the last one went I figured this would be a breeze. But the last truck is a manual so I never dealt with this.

 

[Black_cirrus]

TBI is a stupid simple system to keep running, how was it acting up? Do you have any sort of obd1 scan tool?

 

[joe yuhaus]

TBI is a stupid simple system to keep running, how was it acting up? Do you have any sort of obd1 scan tool?

idles crappy and dies when you stop but only sometimes, plus it makes zero power. I have no interest in throwing money at the TBI or swirl port heads lol. I have a set of recently done vortec heads from a friend an edlebrock intake and cam kit for this motor and it' going back in the 86 the 6.0 is coming out of. for now with just a holley but eventually will probably put a fitech efl throttle body on that too.

 

[EDS_5_OH]

We're running a 1992 4L80e from a 454 suburban on my son's 1990 K1500 with a 5.3 ls swap. Nelson performance did the tune and built the harness. Works fine.

 

[Supercharged111]

Problem with doing it the way you want is you'll still have to fork over the cash to tune the TBI PCM to shift the trans the way the 6.0 wants. 6.0 will happily shift WOT at 5500 RPM, TBI tables will shift like absolute crap. The simplicity of the FITech is inducing unnecessary complication to this swap.

 

[joe yuhaus]

Problem with doing it the way you want is you'll still have to fork over the cash to tune the TBI PCM to shift the trans the way the 6.0 wants. 6.0 will happily shift WOT at 5500 RPM, TBI tables will shift like absolute crap. The simplicity of the FITech is inducing unnecessary complication to this swap.

its actually not, already dealt with the issue I think eveyone else is doing it the over complicated way. here's what you need same as when you carb a TBI truck all you need is TPS VSS CTS and an rpm signal. then the trans will run and shift just fine. the engine is stand alone same as when you convert to carb and old style hei.

 

[Supercharged111]

You didn't read my post at all. It will shift fine for a legless TBI engine. It's going to suck for a 6.0. TBI shifts around 4500 WOT, 6.0 wants 5500. Everything under the curve will be skewed too. You'll need to flash a chip for the TBI computer to correct the shift points for the 6.0.

 

[joe yuhaus]

I mean if you get a complete motor with the stock harness and CPU by all means do it that way but that isn't the setup I had. I got a lq4 with everything but someone else had bought the CPU and harness. since it went in a old 4 speed truck first the kit from summit was perfect. had everything I needed nothing I didn't no waiting for tunes just plug and play exactly as advertised.

 

[joe yuhaus]

th

You didn't read my post at all. It will shift fine for a legless TBI engine. It's going to suck for a 6.0. TBI shifts around 4500 WOT, 6.0 wants 5500. Everything under the curve will be skewed too. You'll need to flash a chip for the TBI computer to correct the shift points for the 6.0.

then why dont guys running carbed 6000rpm motors have to do that? or the three Cummins swap guys I talked too? which run at much lower rpms.