Built tbi vs ls swap

[Nw2000]

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

 

[PlayingWithTBI]

What part number are those aluminum heads you mentioned just wondering.

Here's the heads mentioned. I've had them on mine for 3+ years, they flow better than Vortec heads and will handle up to .520" lift but the valves (2.02/1.60) will probably start floating above 5500RPM. I'm shifting @ 5000 to 5350 RPM. Yes, you'll need to tune it for better results if you go with a bigger cam too. I'm running a bored 46mm Throttle Body with 20PSI fuel pressure.

https://www.summitracing.com/parts/sum-162108

 

[PlayingWithTBI]

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 don't have any dyno slips but, I think I'm somewhere around 325 - 350 HP. When my truck was stock with 3.42 gears I ran 0-60MPH in 11.2 Seconds. Now with some go fast parts and 4.11 gears I'm under 7 seconds. It idles smooth and has plenty of low end torque.

 

[Nw2000]

I don't have any dyno slips but, I think I'm somewhere around 325 - 350 HP. When my truck was stock with 3.42 gears I ran 0-60MPH in 11.2 Seconds. Now with some go fast parts and 4.11 gears I'm under 7 seconds. It idles smooth and has plenty of low end torque.

That sounds about what I want. What’s the specs on your engine and what did you do for your tranny to handle that? I have a 4l60e in mine.

 

[Nw2000]

I don't have any dyno slips but, I think I'm somewhere around 325 - 350 HP. When my truck was stock with 3.42 gears I ran 0-60MPH in 11.2 Seconds. Now with some go fast parts and 4.11 gears I'm under 7 seconds. It idles smooth and has plenty of low end torque.

And would you trust it for a daily driver scenario?

 

[PlayingWithTBI]

What’s the specs on your engine and what did you do for your tranny to handle that?

OK, it's an 88 with a stage 2 (600HP) 700R4, I blew 2 before this one. Without looking at my build sheet, from top to tail pipe, the 46mm TB on Edelbrock 3704 intake manifold, EP381 vortec fuel pump, those heads, Lunati 10120700LK cam with 1.6 full roller rockers (.468/484 lift), stock pistons, crank, and rods, Shorty headers, JBA mandrel bent Y pipe to 3" single exhaust, high flow Cat, and Borla Pro XS straight through muffler. For controls and tuning I have the EBL Flash-II and a WBO2. The EBL doesn't do electronic trans though. All in I have about $8K in it including the $2300 for the trans shipped to my house. My son and I did all the labor so I saved a bunch there. This was over 3 years ago and prices have gone up a bit since then. For example those heads were $200 less when I bought them.

And would you trust it for a daily driver scenario?

Yes. If I had to do it over, I'd put in a roller cam since I discovered my block has the bosses for the spider and holes for the cam trust plate too.

 

[Ken Hunt]

I am figuring out what I need for a 350 rebuild for my '95 GMC. I have the junk stock TBI heads and intake, but the 10243880 block is capable of upgrading to roller cam. Would like to go with the better-flow Edelbrock heads and intake like I have seen specified on the performance threads, and since I am only wanting a mild performance boost to low 300s for horsepower:

1) can I opt to keep stock pistons or do I have Edelbrock spec the pistons
2) I want to stay with pump gas and emissions, what compression am I targeting
3) will the Edelbrock heads allow me to bolt the same accessories or do I need to go with serpentine belt set up

 

[red98]

No I get it that more info may be needed to get the build squared away. This thread was just simply asking about engine performance though. What part number are those aluminum heads you mentioned just wondering.

Budget? Thats gotta be one of the main questions here. There are infinite solutions to this issue, but the budget is going to narrow it down the most compared to any other variable. If you have 10k then just LS swap it. If you have $1500 then the 5.7 vortec might be worth swapping in.

 

[PlayingWithTBI]

1) can I opt to keep stock pistons or do I have Edelbrock spec the pistons
2) I want to stay with pump gas and emissions, what compression am I targeting
3) will the Edelbrock heads allow me to bolt the same accessories or do I need to go with serpentine belt set up

Flat top pistons will give you more compression. So will the Edelbrock heads since they are 62cc while the 193 swirl port heads are around 65cc.

If you go too crazy with compression you'll need higher octane. I'm running 91 in mine and could probably get by with 89 and less spark in my tune.

The accessories will bolt right up to these heads. They have the same angle (72* IIRC) intake bolt holes in the center 2 on each side too.

 

[stutaeng]

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.