Built tbi vs ls swap

[Nw2000]

Sorry Man, didn't mean to sound like a a$$. I failed to see your HP/TQ goals. I think you can do either with those numbers.

I would vote for the LS platform. They are cheap (they are everywhere,) reliable and make good power. That's why they go into everything. Yes, they are not original, and some people don't like that. It's a matter of opinion on that. You will have to assess that. The other point is that the aftermarket performance of the LS is just everywhere! With the abundant supply of cheap aftermarket power adders, folks are comfortably making 600 HP+ from $500 junkyard engines! That's insane.

On the TQ number, go for displacement. 5.7 TBI or 5.7 Vortec I'd say have better low-end torque than a 4.8 or 5.3 LS. You'd have to get a 6.0 LS to get into that low-end torque, and those typically command a higher price.

On the HP numbers, I'd say LS>5.7 Vortec>5.7 TBI.

The other thing to consider is transmission and controls. If you have the non-electronic transmission, aftermarket stand alone controllers get expensive. So an LS can get expensive after all. Probably no less than $2,000 to the 5.3 swap if you are thrifty.

My brother has a 90 RCSB with a aftermaket crate (JEGS, I think) TBI that he bought like that from the previous owner. I think he said it's started burning oil, so we have thought of going LS. He wants to keep his 700R4 and I think it's just better to get an 5.3 LM7/4L60e and go. His is like a second daily driver, kinda rat-rod looking truck. LS makes perfect sense for his case, but I told him plan on at least $1500 and truck being down for like 4-6 weeks before being reliable again as a daily driver. I think a 5.3 LS out of the box would almost make 300 HP?

Either way, you are looking at spending some coin. I hope this helps.

No worries it’s all good. Honestly from what I’ve been reading in this thread in leaning more towards a 5.3/6.0 and get a matching tranny from the same truck. Kind of intimidated with the wiring and fuel modifications but I guess you’d run into some of that any other avenue you go down.

 

[CrustyJunker]

Do any of you guys have any experience on tbi making power over 300hp? What all has to be done to make it reliable?

I do, ~345 HP. Best advice to make it reliable (if you want to stick TBI)? OEM style everything if you can help it.

Examples - keep your OE sensors, heavily recommend running the DynamicEFI EBL Flash over "chipping." -It's a modified OEM ECM available that uses your factory wiring harness.

Fuel system - Delphi/ACDelco EP381 fuel pump (essentially OEM, but higher pressure/flow that drops right in your tank with cross-country reliability), use your existing Rochester GM throttle body, or buy a bored small block throttle body or big block throttle body, and big block injectors (again, higher flow rate for performance, reliable).

If you want more details, let me know. There's no wrong decision. LS is much better supported these days than when I built my TBI build...And high quality TBI replacement stuff is getting harder to find since the technology is old. Either one will net you lots of fun. I'll also agree to go bigger than 5.3 if you can. These trucks aren't super heavy, but displacement is king!

 

[RawbDidIt]

The 4l60e came in 5.3l LS powered light duties, so you don't need to swap transmissions for what you're looking for unless your current transmission is going out.

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[Nw2000]

The 4l60e came in 5.3l LS powered light duties, so you don't need to swap transmissions for what you're looking for unless your current transmission is going out.

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My truck is a 1995 so would the 4l60e on it work even thought it’s an obd1?

 

[Schurkey]

My truck is a 1995 so would the 4l60e on it work even thought it’s an obd1?

What are you going to use for a trans controller?

I'm guessing the TBI computer isn't going to be happy with an LS under the hood. Or the LS being happy with a TBI computer.

So does the LS computer from the donor vehicle talk to the TBI transmission? I bet it does, if the wiring is pinned to the correct places.

 

[Nw2000]

What are you going to use for a trans controller?

I'm guessing the TBI computer isn't going to be happy with an LS under the hood. Or the LS being happy with a TBI computer.

So does the LS computer from the donor vehicle talk to the TBI transmission? I bet it does, if the wiring is pinned to the correct places.

Yeah honestly I’m not too sure if it would work or not. Mechanically it definitely would but who knows.

 

[stutaeng]

Yeah honestly I’m not too sure if it would work or not. Mechanically it definitely would but who knows.

If it's the electronic version of the 4L60, then it should work with the LS.

The late TBI had electronic controlled tranmissions just like the Vortec.

It's the non "e" 4L60 the one that wouldn't work as a plug'nplay.

 

[RawbDidIt]

My understanding is that the 95 is a 4l60e, prior to that they were all just regular old 700r4's. Wouldn't be the first time I was wrong though, worth further research for sure.

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[PlayingWithTBI]

Examples - keep your OE sensors, heavily recommend running the DynamicEFI EBL Flash over "chipping." -It's a modified OEM ECM available that uses your factory wiring harness.

Another option is keep your 7427 PCM (I think you have), so you can still control your trans, and get a real time emulator such as the APU1 or Ostrich 2.0 and tune with them. A little more hands on since the EBL Flash-II will self learn your fueling tables but, There's Excel spreadsheets around that will help dial it in with data logging and plugging in the numbers then downloading to your PCM.
http://www.moates.net/realtime-emulation-c-95.html

Anyway, if you want to go LS, prepare yourself for changing out the PCM and wiring harness. Its PCM goes under the hood where yours in behind the glove box. Keep in mind the slightly modified TBI 5.7 can out tow and accelerate a stock 5.3 LS all day long.

 

[Dropped88]

4l60e started in 1993 and 95 is a standalone year even with trans so that'll be a no go with the LS. You can make a 97-98 trans work but best to stay 99+.

Best just to get trans with the engine