[konnie336]

how much hp does a carb lt1 engine have

[zildjian4life218]

Originally Posted by konnie336

how much hp does a carb lt1 engine have

Need to know a lot more info to figure it out. From the factory I believe they made around 300 with the fuel injection so will depend on carb and intake u choose. But then again depends on what car the motor came from.

[eocoolj]

are you referring to the original LT1 from the early 70s, or the LT1 from the 90s?

[konnie336]

It came from a 1995 impale it has a 750 edelbrock and Holley intake on it

[automotive breath]

From what I have seen replacing the FI setup on a LT1 with a carb. and a
regular intake doesn't change the power much if any. The production set
up is capable of plenty of power.

[eocoolj]

from wikipedia:

A retuned LT1 5.7-liter (350 cu in) small-block V8 was standard on the Impala SS, making 260 horsepower (190 kW) and 330 pound-feet (450 N·m) of torque (retuned from the prototype's 300 horsepower (220 kW) rating). The primary difference between the LT1 in the Impala and the LT1 that was in the Corvette and Camaro was that the Impala engine was fitted with cast-iron cylinder heads instead of aluminum ones, and a camshaft that was designed more for low-end torque than high-end horsepower. Another difference was that the Impala LT1 had 2 bolt main bearing caps while the Corvette LT1 had 4 bolt main bearing caps.

No idea what your carb setup has done to HP output (may have even gone down if not tuned properly or with a poor intake choice), but I would guess somewhere between 250 and 275.

[konnie336]

Okay what can I go with to reach 400hp with the setup I have now and what transmission to

[oldbogie]

Originally Posted by konnie336

It came from a 1995 impale it has a 750 edelbrock and Holley intake on it

You need to check the casting number and or engine ID to determine if you have an cast iron LT1 or a L99 they look the same from the outside but are about 90 cubes different.

10208890 is L99 at 4.3 liters of V8 not V6
10125327 is 5.7 liters of LT1

Bogie

[bandit327]

yeap ive seen a lot of people that get tooken for the 4.3 and tear it down and be pissed cause its not the 5.7 lol,the 96 lt1s have knock sensors so that a lil info

[eocoolj]

Originally Posted by konnie336

Okay what can I go with to reach 400hp with the setup I have now and what transmission to

I'm assuming this isn't in a car yet? If you aren't married to it, I would seriously consider an LS engine. Some of them are putting out close to 400 hp bone stock, and most of the rest of them can do 400 (flywheel) hp with just some headers, maybe an intake, and a good tune. The truck versions are pretty reasonably priced.

Not overly familiar with the LT engines, but I would guess you will have to do a bit more massaging to get 400 hp out of it. Nitrous will get you there quick if you dont need it all the time and are willing to "cheat." I'm sure others will chime in with other ways to reach your goal.

[nick8]

Originally Posted by konnie336

Okay what can I go with to reach 400hp with the setup I have now and what transmission to

I love LT1's. Although you have good flowing heads (IIRC Vortec heads were designed based on 1995 iron LT1 Heads) you will need head work to get you there.

Head work
cc503 Cam
1.6 RR
Headers

I think this will put you very close to your goal.

[texas97z]

400 hp, where at the fly? Building "the less popular" GM efi engines is what I do. and 400 fwhp is easily achievable without doing any head/intake porting and certainly no aftermarket heads either. Basic bolt ons like headers, 52mm throttle body, cold air intake, and a good tune have yeilded results for several ltx f body guys of 375 fwhp, b body would be harder as header selection is limited to upswept mid's from what I seen without shelling out MEGA bucks. But with the right combo you could get 330-350, then pick out the right cam and again the right tune, and you could exceed your goal of 400 hp.

400 rear wheel is another story, my ported heads/intake 383 GM847 cam true dual x pipe car does over 400 rwhp/400 rwtq, but it was a lot more work...

But I would say the guys I know who have swapped to carb said it wasn't worth the hassle or expense. You probably got the engine with intake manifold(if not they are very cheap used $50) where as finding a used carb LTx manifold if you can will run $200($300 new). If the intake was on it, injectors and fuel rail may have been as well. If not again they are cheap used and in good working condition(less than $100 for all). I will be hard to find a good carb setup for the same price, unless you already have the right carb.

Not trying to talk you out of it at all, just trying to give you some thing to think about if you hadn't. Hope this helps,

Josh

[konnie336]

What about if I port the heads and get a lt4 hot cam kit
will this help with reaching my 400 goal

[nick8]

From what Texas97z said you may not have to port the heads. He says he builds the LT1 engines so he should know better how to reach your goal. The question is: 400 flywheel hp or 400 rwhp?

[stroker_SS]

Originally Posted by eocoolj

consider an LS engine. Some of them are putting out close to 400 hp bone stock.

Most of them put out MORE than 400hp on a stock tune(with the exception of the 5.7l ls1/ls6).

These engines are considerably more expensive than a old LT1 though.

For which reason people choose the LS BASED GenIII/IV truck engines. The G-III 5.3 truck engine puts out more than an LT1 and can be had for around 700 intake to oil pan in running condition. Most all of the parts between the LS series engines will swap over to the truck engine.

Finding headers for a GIII/IV or LS type engine is a whole different story, usually rangine upwards of $600 for a set of long tubes.