Is 300 hp possible from a tbi

[Supercharged111]

It can be done. Its not gonna be cheap and it just aint gonna work for long with a 4l60e or a 700r4.
By the time you get done .
Though I hate to say it.
LS swap it.
300 hp easy and reliable.

I'd agree if OP was after 400hp, but 300hp is easy. 4L60 doesn't car what the 300hp comes from, it'll die just as easy. The torque will do it in though.

 

[westsoundred]

as I think through this, how much am I going to have to beef up my 4l60 in order to handle the new power plant? Lets say I punch out 300 hp and 375 ft/lbs, will I fry the tranny?

I'd like to rebuild the 4sp auto, not too interested in a 5 speed (conversion time) or 4l80 unless it takes the same TV cabling.

 

[df2x4]

as I think through this, how much am I going to have to beef up my 4l60 in order to handle the new power plant? Lets say I punch out 300 hp and 375 ft/lbs, will I fry the tranny?

Considering I roasted two 4L60Es behind a stock 4.3L V6, I would be thinking about a 4L80E swap if I were you personally.

 

[westsoundred]

will a 4l80e work with my tbi? what about the loss of that tricky TV cable?

 

[Gramps]

before you start worrying about swapping 4l80’s, what are you trying to do with the truck? Serious towing? Off-road? Generally beating the tar out of it?

 

[df2x4]

will a 4l80e work with my tbi? what about the loss of that tricky TV cable?

I'm sure you could figure out a way, but it might take some doing. The biggest obstacle I can think of is finding someone to tune your PCM to run the 4L80E. That and I'm not familiar with the wiring on the 700R4, I'm sure you'd have some changes to make there that I'm not aware of. The 4L80E was introduced in '91 though, so if your PCM is that year or newer I'd think it would be capable of running a 4L80E.

 

[L31MaxExpress]

I'm sure you could figure out a way, but it might take some doing. The biggest obstacle I can think of is finding someone to tune your PCM to run the 4L80E. That and I'm not familiar with the wiring on the 700R4, I'm sure you'd have some changes to make there that I'm not aware of. The 4L80E was introduced in '91 though, so if your PCM is that year or newer I'd think it would be capable of running a 4L80E.

93+ is the best TBI PCM. Used with the 5.7 and a 4L60E or 4L80E. For a 4L80E from a 700r4 you have to add 16 wires and a later model VSSB with two speed signal outputs. Not a big deal IMO. Well worth the durability of a 4L80E over a junk ass 700r4 or 4L60E.

 

[westsoundred]

before you start worrying about swapping 4l80’s, what are you trying to do with the truck? Serious towing? Off-road? Generally beating the tar out of it?

Bouncing around on back roads and the occasional logging trail. But mostly, out of fear that the torque resulting from my 300hp quest will torch my current tranny

 

[westsoundred]

I'm sure you could figure out a way, but it might take some doing. The biggest obstacle I can think of is finding someone to tune your PCM to run the 4L80E. That and I'm not familiar with the wiring on the 700R4, I'm sure you'd have some changes to make there that I'm not aware of. The 4L80E was introduced in '91 though, so if your PCM is that year or newer I'd think it would be capable of running a 4L80E.

dod the early 4l80e have the TV cable? My truck is a 1992

 

[westsoundred]

93+ is the best TBI PCM. Used with the 5.7 and a 4L60E or 4L80E. For a 4L80E from a 700r4 you have to add 16 wires and a later model VSSB with two speed signal outputs. Not a big deal IMO. Well worth the durability of a 4L80E over a junk ass 700r4 or 4L60E.

Did you keep any wiring diagrams?