i purchases a 96 lt4 car with a bad lifter and some cam damage.with over a 100k on the lt4 motor i have decided to replace with a 383.im not sure if i should re use the lt4 heads.i can buy a complete motor with heads or without.

 

I wouldn't put 100K heads on a newer block.

 

Ditto the rebuilts probably have at least a valve job and hopefully fresh springs on it. Some porting would go a long way

 

after pricing LT4 parts, you may decide replacing the cam and some new lifters is the way to go...just sayin' .

 

If you rebuild the block, you have to re-do those 100K miles heads.

You can get a valve and port job to beef up the 383. Elliot Portworks has done few heads for CF members including myself. Visit his website, look, read and give him a call. A reliable local machine shop can also do that type of work.

EP also ported my intake.

 

i was planning on re building the heads.i was mainly wondering if the lt4 heads have anything special about them.its only $500 difference on the motor with no heads.the motor with the heads have been dyno tested to 430hp.this is the description of the heads with the motor.sounds like rebuilt lt1 heads.The cylinder heads recieve all new guides and positive seals, with a 3-angle finish on the 1.96"x1.55" valves and 100# springs. The heads are surfaced, providing the correct clamping force.

 

Stay with the LT4. It's got a few benefits over the LT1. The heads flow better and it's got 10.8 compression instead of 10.4. The crank is radiused and has a 6300 RPM redline. The timing chain is a roller instead of a butt link and the LT4 has no EGR. It also has roller rockers and bigger valves.

As you thought, it is LT1 heads on the other engine because the LT4 has 2.00" valves in stock form and taller runners. The LT4 can potentially make more power and be more durable because of the radii cut on the crank. Make sure the engine you buy has factory 4 bolt mains also.

Don't trade yours in on the new engine because LT4 parts are bringing a premium.

 

i just found out the lt4 heads are taller and the intake is different from the lt1.and as you guys mentioned the block has advantages 4 bolt main as well as others.heres my problem.its the same money to buy a complete engine or re build the lt4.i may have to get a new intake but i would still have the lt4 engine.he charges no core.

 

Here is the thing.

When you build your LT4 - you know what your starting with. You also can buy the best internal componets you want/can afford to put in the engine.

Personally I've always tried to tailor my work to the customer and educate them on quality v/s $$$ spent. Last 5-10yrs I have also spend a bunch more time that I think I should have to managing expectations.... Don't come to me telling me about the build you saw on www.xxxx.com about the 530RWHP 9second F body using a stock LTX bottom end...... I know this sounds like an extreme example but some people really don't know BS when they step in it (or click on it).

I have a very simple method when I make recomendations on engine builds. Lets break this down and take it one thing at a time.

1. Cost.
How much do you honestly have to spend on the engine?

2. Performance.
What do you expect from the engine/car? HP or ET, driveability, mileage, ect.

3. Peripherals.
How much do you have budgeted for headers, clutch, gears?

4. Legality.
Emissions legal build?

Once you answered those you can have someone who knows what they are talking about start to price stuff out and see how good of a deal your "complete engine" is v/s something else.
Will

 

How much is he wanting to charge for the 383 LT1 engine? What size rods did he use? There's a lot of ways to very cheaply make a 383 and there are several ways to rebuild yours.

One of our sponsors has a balanced 383 rotating assembly for a little less that $1000. That would include a crank, pistons, rods, bearings and rings. You can get your LT4 bored .030 over for around $150.00 and clearanced for another $100-$150. Lifters will be around $130 and a cam around $250 or so. You could have a good street 383 LT4 for about $2000-$2200 if you choose parts wisely. A local machine shop would probably charge around 300 or so to assemble the bottom end and do the cam and bearing install if you'd rather not do it yourself.

A local shop around here just assembled an engine for a friend of mine and the machine work was:
Rebore Cyl with torque plate hone $150.00
Assemble piston and rods $40.00
Install cam bearings $35.00
Hot tank and clean all passages $50.00
Polish the crank $35.00
Engine assembly was $200.00

It's not as expensive as most people think and you'll know exactly what is in your engine.

 

If you oder the shortblock have it torn down and checked at least.Yes,you should'nt have to but it is far cheaper than a blown motor later beacuse "it was new".

A fresh valve job and springs on your heads will be sufficient.I have seen "ported" LT4 heads by a known guy lose performance.The runners are large and don't need to be ported to gain hp at the expensive of low end and midrange unless you are building a high rpm drag motor.A lot of people may disagree on this but it is my experience.I will be glad to share my experience and who it was via pm with the op.
Some bowl work and a killer valve job yes but I would'nt touch the runners.

 

here is the price and description.i just dont know if i should give up the lt4 whitch just has a bad lifter and needs a cam.or should i just have him re build the lt4.if i have him build me a 383 it is the same price as re building the lt4.almost seems better for me to keep the lt4.and buy another intake. Bore and hone cylinders- Deck block surface for positive gasket retention- grind for stroker clearance. The cylinder heads recieve all new guides and positive seals, with a 3-angle finish on the 1.96"x1.55" valves and 100# springs. The heads are surfaced, providing the correct clamping force.

The "EAGLE" cast 3.75" stroke crank and I-beam rods, are balanced, allowing the use of factory flywheel and front pulley! SpeedPro (10.4to1) compression, dished pistons (#H859CP) are fitted with SpeedPro moly rings. The camshaft providing 385hp and 410ft.lbs.torque, spec's are (220/224`@.050" with .505" lift on 112`LSA), with the factory steel 1.5 ratio rockers. Other cam grinds are available, call for details. A new Cloyes H.D. timing set and roller lifters are installed, with valvetrain preset, for quiet operation. A complete gasket set and NEW oil pump with screen are included, allowing easy completion of engine. Aluminum 1.6 ratio roller rockers available, for $200.00 extra.

This engine is hand fitted and assembled, by an ASE certified Master Machinist (me), with 26 years experience. Quality parts and workmanship, carry a 90 day parts guarantee, after start-up. This engine is built to order, taking appox. 3 weeks after recieving payment.

No core/exchange is required, saving you hundreds$$

Aluminum head or Iron head LT1, cost the same, only $2399.00 + freight.

 

I don't have a crystal ball so I don't know about c4 values in the future ....there are many members of this forum that will tell that C4's have no value and never will have any value. But at my age and with the benefit of hindsight, I can say that was said about c3's, c2's, and c1's. Have you priced any C1's, c2's or early c3's lately ? You could send your kid to college for the price of some of those car's; but what's the biggest difference between expensive and uber expensive ? Matching original engine numbers. Sure, back in the day, swapping out that original 283 for a 327 or an original 327 for a 350 must have seemed like a great idea, but in retrospect it was probably one of the worst decisions EVER. By all means build up a 383, but do it with your original LT4 block.

granted there may be some delay, and it may be slightly more expensive than some prefabbed crate type engine, but in the short and long run I just don't see a down side to rebuilding your LT4 block.

any other opinions out there ???

 

It cost money to go fast. Plain and simple...

 

LT4 heads will make more power simly because they flow a good 30-40 cfm right off the bat. Your stroker will be wanting that, the LT1 stock head will choke on the stock heads quickly

 

If you are saying in message 12 you can buy that motor with Aluminum heads ,( I'm assuming these are LT1 heads) for $2399.00 and no core exchange you better jump on this and pick up an intake on e bay for $75.00 install this motor in your car. Then go through the LT4 and rebuild it, to keep a numbers matching car you will need this motor and since you will be driving the car with the LT1 you can take your time and price out the parts for the LT4 motor because you will find out they go from high to very high when you say the words Corvette and LT4. One last thing i would make sure that whom ever it is selling the engine your talking about, before you give him a cent I would make sure it's legit because for a ASE certified Master Machinist (me), with 26 years experience, I would have to question some of the statements made in that ad.