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LTx Replacement... or Mod an Old School 350 SBC


Guest Mike

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Guest Mike

Pop N Wood

 

Thanks for the heads-up on LS1 prices. I have so much to do to this car that I really must keep prices down. I'm really beginning to see that my best option is to tweak the power plant I already have.

 

I think the best mods are better-flowing aluminum heads, better roller cam/lifters, better SS exhaust... all tuned to provide the HP and torque in the 1500-6500 RPM range for a street/road car running on 93 octane pump gas. I might opt for a 400 crank to make a 383 stroker... and keep the RPMs below 6000.

 

What do you guys think... given my $5K or less budget?

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Guest Mike

73LT1Z

 

I actually prefer EFI. It's the modern look I don't want. There are some retro-styled systems out there. Vintage Speed has one for $2600 complete with Megasquirt computer. Although it busts my budget, I might still opt for that one or another oldies-style system. But I think the stacks are too tall to fit under my hood... and they have yet to answer my inquiries about shortening them. If not for the cost and height, I'd go for that system in the blink of an eye.

 

A $2300 hot low-mile gen3 complete... now we're getting somewhere!! Wanna' sell yours :^)

 

EDIT: AND... I could go for the Vintage Speed retro fuel injection setup and STILL keep it under $5K!!!

 

I'll check out the websites you listed. Wish me luck.

 

Thanks!!!

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Guest 73LT1Z

I forgot to mention the book LS1 & LS6 performance- I bought this & it has real good info. Here is a link to Overstock.com, it's under $12 plus cheap shipping.

 

http://www.overstock.com/cgi-bin/d2.cgi?PAGE=PROFRAME&PROD_ID=1113386

 

They added a turbo & larger injectors to the 4.8 stock motor & made close to 500 hp on 8 psi of boost. There are a few dyno charts as well for the modded 6.0 & LS1 motors.

 

EDIT

I was wrong about the 4.8 turbo motor output :eek: .

 

542@5100/603@4400

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Guest 73LT1Z

Here you go...

-BUILT Complete FRESH Carb'd LT1 Longblock. CARB TO OIL PAN. Took motor out to clean up engine bay and to do gaskets & to verify the condition of the motor - It is EXCELLENT. The motor hasn't even been ran since all the brand new gaskets and ARP Head Bolts.

 

---Never been sprayed!--- Was going to this season.. But not anymore

 

*Professionally assembled shortblock - TRW .040 Over Forged Pistons.

balanced and blueprinted. Motor is still in new condition. It has less than 1,000 street miles on this motor.

*Moly Rings

*Brand new Felpro 1074 Head Gaskets

*Brand new gaskets all around. 1 Piece oil pan gasket, everything.

*Custom Comp 233/236 Cam with 109LSA. Drove and idled perfect on the street - This is a perfect N/A or nitrous cam.

*Holley ProForm 750 Carb. Perfect condition.

*GM Performance Intake

*BRAND NEW ARP Head Bolts Torqued to spec. Just put these in this past week as well as the gaskets.

*Professionally Ported Heads - Said they are 2.02I/1.60E

*1.6 Rocker Arms

*Everything ready - Timing chain, cover, etc. All mounted.

*Comes to right around 10.25:1 compression - PERFECT Pump gas car.

 

$1,500 assembled and ready to go.

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Guest Mike

Somone just offered to sell me a low mile (22K) LS1 "complete" with ECU, harness... everything... for $2500. Assuming the best, is this a good price?

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Guest 73LT1Z

For just the motor, that is a so-so deal. I've seen motors & trans go for that amount on Ebay, and you can definitely do better on the LS1 message boards.

 

Here is a 1999 LS1 (motor only) for $1100:

http://cgi.ebay.com/ebaymotors/1999-Corvette-LS1-Engine-Motor-60k_W0QQcmdZViewItemQQcategoryZ33615QQitemZ8072028113QQrdZ1

 

This seller always seems to have LS1 combos for sale in Orlando:

http://cgi.ebay.com/ebaymotors/98-99-00-LS1-LS6-engine-4L60-transmission-Corvette-GTO_W0QQcmdZViewItemQQcategoryZ33615QQitemZ8070672581QQrdZ1

 

To make it "complete", you are looking at a harness (can be had used for around $200), computer ($100), and accessories ($200), so you'd have around $1600 in an $1100 motor.

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Guest Mike

Wow... a "buy-It_now" price of $1100... that's a big price difference... this is for one that's been replaced with a fresh rebuild and that worries me.

 

Man... this is a real quagmire... trying to muddle through all the different iterations of the LTx and LSx engines... and the many options available for each... not knowing the "real" mileage or the "real" condition of a used or rebuilt engine.

 

I'm feeling fairly "stoopid" :confused: right now folks. I am learning though.

 

TO SUM THIS UP... SO FAR: This is gathered from another forum too... so you could say this is a "hybrid" summation:redface:.....

 

I probably shouldn't bother exchanging complete engines UNLESS I skip to an LSx, right? Used or rebuilt LS1's have become common and are very affordable, right? It's easy to coax 450-500 HP from an LS1 with a mild performance roller cam, LS6 heads, LS6 induction system, a good exhaust, and re-tuning, right? High performance aftermarket induction systems with better than LS6 performance... and with the exotic look I want are available but pricey, right? An LS1 is all aluminum and therefore weighs a couple hundred pounds less than an all iron 350 SBC, right? If I opt to keep the old 350, just add better aluminum heads, healthier cam (but streetable with auto trans and stock converter), nice SS headers, performance induction system... all tuned for my preferences... and will easily make 400+ HP, right?

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You are about where I was a year or so ago. Somehow or the other I have talked myself into believing a new crate motor is the only way to go. I could probably save a lot of money scrounging for deals on used stuff. But all it would take is one bad deal to wipe out whatever money I might have saved. But since I don't work in the auto field, it is not like I see used engine deals all the time. It could be a lot of work for me to find a deal. I know I am being overly paranoid since so many guys successfully build from used engines.

 

450-500 is not a given on an LS1 motor. If that is your goal, then from what everybody tells me an LS motor is probably the cheapest way to get there. Supposedly LS engines maintain their street manners at 400+ HP better than the earlier generations, so that is one of the huge advantages of the LS motors. But you will spend some serious money converting a 345 HP Fcar motor to those levels.

 

The weight savings on the LS over an LT motor is more like a 100#

 

Most guys keep the stock LT1-LS1 EFI and build on it.

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Guest Mike
You are about where I was a year or so ago. Somehow or the other I have talked myself into believing a new crate motor is the only way to go. I could probably save a lot of money scrounging for deals on used stuff. But all it would take is one bad deal to wipe out whatever money I might have saved. But since I don't work in the auto field' date=' it is not like I see used engine deals all the time. It could be a lot of work for me to find a deal. I know I am being overly paranoid since so many guys successfully build from used engines.

 

450-500 is not a given on an LS1 motor. If that is your goal, then from what everybody tells me an LS motor is probably the cheapest way to get there. Supposedly LS engines maintain their street manners at 400+ HP better than the earlier generations, so that is one of the huge advantages of the LS motors. But you will spend some serious money converting a 345 HP Fcar motor to those levels.

 

The weight savings on the LS over an LT motor is more like a 100#

 

Most guys keep the stock LT1-LS1 EFI and build on it.[/quote']

 

On the one hand, I have to agree that it's probably better to take the easy/guaranteed route with a crate engine. Time is money and we have precious little of it to waste. One the other hand, crate engines are pricey and I would probably take the chance with the right used motor if everything is included. But I don't want to waste any time searching for miscellaneous parts and pieces. I don't have the time... or the patience :rolleyesg

 

A 100 pound weight savings is relatively insignificant but is still worth about $500 to me since it all comes off the front. Regarding power, I would be happy with 300 HP, plus a 100-150 nitrous shot. However, 450 HP plus nitrous would be a heck of a lot of fun and is worth about $2K to me. In other words a good, strong, "complete", low mile 450 HP LS1 is worth about $2.5K (to me) plus another $1K for labor to install it.

 

I must keep my other goals in mind, such as an exotic induction system costing $1-2.5K, plus interior upgrades ~$1K, plus brake upgrades ~$1K... adjustable suspension ~$1K... wire wheels ~$1.5K... etc...

 

When you speak of an LS1 keeping it's "street manors"... is this primarily due to the updated firing order? Gen1 firing order can be changed with a custom-ground cam, right? Are the other differences important?

 

I still haven't decided whether to update this 350 SBC or swap for an LS1... or later iteration. With enough information coming at me, I'll make a decision soon. I guess I'm just dense-minded these "daze".

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Guest Mike

 

That's a real possibilty. The same seller has some long blocks too and they cost a lot less. Plus, I wouldn't have to pull anything to sell... just bolt on the valve covers and induction system of my choice.

 

You know... I'm really leaning toward a bolt-in gen1 solution. It's easier and cheaper. I really like the LSx power plants... but I'm beginning to realize that I won't gain as much performance, nor lose as much weight as I first thought. A good strong 383 stroker w/ aluminum heads and a trick induction system is looking pretty good to me right now!!

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That's a real possibilty. The same seller has some long blocks too and they cost a lot less. Plus' date=' I wouldn't have to pull anything to sell... just bolt on the valve covers and induction system of my choice.

 

You know... I'm really leaning toward a bolt-in gen1 solution. It's easier and cheaper. I really like the LSx power plants... but I'm beginning to realize that I won't gain as much performance, nor lose as much weight as I first thought. A good strong 383 stroker w/ aluminum heads and a trick induction system is looking pretty good to me right now!![/quote']

If you want to make it really easy and save some money find a local engine builder. Ask around your local track to find some referances and bring him your 350. He can build you a 383 out of the 350 and save you some cash.

I reccomend forged flat top pistons, full floating forged H-beam rods and a forged crank. Add some nice alluminum heads... Here is a link that helped me.

http://forums.hybridz.org/showthread.php?t=109870

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Guest Mike
If you want to make it really easy and save some money find a local engine builder. Ask around your local track to find some referances and bring him your 350. He can build you a 383 out of the 350 and save you some cash.

I reccomend forged flat top pistons' date=' full floating forged H-beam rods and a forged crank. Add some nice alluminum heads... Here is a link that helped me.

http://forums.hybridz.org/showthread.php?t=109870

 

Thanks WickedWild. I'll ask around here in the San Antonio area. I just wish an LS1 swap was easier/cheaper. This little car can never use all the low end torque a 383 stroker can make. Even with suspension mods, Quaife differential, and fat tires, the rubber will just melt away at full throttle.

 

I would definitely prefer a smoother power band with a strong-pulling top end. On the other hand, a really good 383 stroker will be mighty nice in a 2600 pound car :mrgreen:

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From the thred I linked too...

"Am I wrong in assuming that a 383/396 is only good for stump pulling torque?"

 

yeah' date=' your wrong, here! the cam,compression,and heads have a good deal more to do with the way the engine responds, stroke alone is basically not a big factor,think about it, a 427 big block engines known as a high rpm screamer, it has a 3.76 stroke just like a 383,your 305 had a short stroke,(3.48" just like the 350, but it was not a high rpm combo! yet a 3.48" stroke in a 350 can be!

build the engine as listed with the cam and compression listed, ETC. and youll see a totally differant style engine that wraps up quickly to 6700rpm, with a torque curve that starts off low and goes up rapidly

maybe one of the guys here can post a dd-2000 dyno curve to show you[/quote']

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