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GenIII or IV vs Gen 1 Engine Upgrade Costs

hefavitzen

Scrambler Junkie
BENEFACTOR
Gold Member
Lifetime Member
City
Rock Hill
State
SC
I have been wrestling with the cost of engine replacement and cost vs. drive-ability. I have received a lot of advisement (thanks to all!) and have talked to many many folks.

So, I have made this handy comparison chart to assist me in tracking expenses. I am counting on a cooling fan upgrade to fix my cooling issue since my current fan is tiny with a tiny shroud.

Cost of an LS/Gen III/IVPro - Power
Con - 100K already on the clock
Con - LOTS of additional work to
install, I cannot install in my driveway
Cost of a Performance "Crate" motorPro - Power
Pro - Easy to install as it is a drop in
Con - expense
Cost of a GM350 / 290 HPPro - Might be reasonable power
Pro - 87 Octane
Pro - drops right in to existing setup
Con - might be bored if the power is weak.
Part or ProcessEstimated CostVendorPart or ProcessEstimated CostVendorParts or ProcessEstimated CostVendor
Engine 5.3 / 6.0$1,500EbayEngine$5,000.00Pace PerformanceEngine$2,100.00GM Performance
transmission 4L60$800EbayNew Carb$500.00New Carb$500.00Holley
trans to transfer adapter$626www.novak-adapt.comHeaders$300.00Headers$300.00Sanderson
motor mounts$207www.novak-adapt.comExhaust$400.00Exhaust$400.00
Taurus fan and wiring$165Taurus Fan and Wiring$165.00Taurus Fan and Wiring$165.00
ecm flash$200?
wiring$450?
drive shafts?$400?
Exhaust$400?
Regear Axles to 4.something$800
Fuel System Update$300www.novak-adapt.com
Install Labor$2,500estimated
Total$8348$6365$3465


Has any one used the GM350 / 290HP engine before? Any idea if it is worthy of the cost?

I know the first thing you have to assess is what you are going to use the vehicle for.
My vehicle will realistically see 4000 miles a year of mostly highway driving at 70mph to take me to and from work. The rest of the time will be around town and probably two or three weekends a year of very light off roading. I do not plan on ever selling it, so that is not an issue.

I can do limited work in my driveway. However, it is completely uncovered and unsecured and my wife will get tired of looking at it torn apart after a few months. Due to this, I am factoring in labor for the LS engine, but can drop in in my driveway if just mating a new engine to the transmission currently installed.

Any input would be helpful and I am more than happy to update this spreadsheet.
Here is a link to the actual spreadsheet. https://docs.google.com/spreadsheet...YwRzNHNXYxRHBRTzR6c3pxUGc&usp=drive_web#gid=0
 

BRKLYNZ28

Scrambler Junkie
Lifetime Member
City
BROOKLYN
State
NY
I see 450 for wiring. Shouldn't cost you that much unless your buying factory ls wiring manual. . Also labor I assume you found a shop that would take that on. Most shops I know wouldn't. Probly save more money on the fan thing also used on ebay.. you also forgot if u dont have the right transmission then the main shaft has to be replaced and thats a rebuild of 800 bucks. And a low stall converter and shifter... ls is the cooler engine. But the simpler 350 is easyer to fix and parts are everywhere. . I think the 5000 for the 350 is way to much. I would shop around on that. .

Sent from my SPH-L900
 
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hefavitzen

Scrambler Junkie
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Gold Member
Lifetime Member
City
Rock Hill
State
SC
I see 450 for wiring. Shouldn't cost you that much unless your buying factory ls wiring manual. . Also labor I assume you found a shop that would take that on. Most shops I know wouldn't. Probly save more money on the fan thing also used on ebay.. you also forgot if u dont have the right transmission then the main shaft has to be replaced and thats a rebuild of 800 bucks. And a low stall converter and shifter... ls is the cooler engine. But the simpler 350 is easyer to fix and parts are everywhere. . I think the 5000 for the 350 is way to much. I would shop around on that. .

Sent from my SPH-L900

The shop is Adam Brown Customs as he has never done one and thought we could do it together and figure it out. I am cool with that but the costs of the parts and pieces is making my dizzy and worried as I like to stick to a budget; I fear being nickle and dimed into bankruptcy.
I talked to a number of shops; the local 4WD store recommended a local installer and I went to them. They told me they do not do them period unless I had a $20k to spend as it is a lot of trouble for them. They said, "put in a ZZ4 and be done with it". A ZZ4 is $4k from GM, BUT, requires 91 Octane fuel...OUCH!.
The referenced $5K from Pace Performance comes with Holley Fuel Injection.

There are a BUNCH of local builders as this is NASCAR country. Just not sure who to trust.

I have to be as cost conscious as any average Joe as my checkbook is not limitless nor is my wife's patience. :) She'd like to see me driving it instead of working on it.
 
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spankrjs

Scrambler Junkie
Lifetime Member
SOA Member
City
Biloxi
State
MS
Simple, cheap, bolt in, easy wiring, wont tax the rest of your power train - Just get a TBI 350 out of the junk yard. Rebuild the engine if necessary. The wiring is easy, the injection is simple/reliable.

I have one of these engines in my Tan Scrambler. On paper, they say they only make 200-220HP. Why this isn't dazzling, it provides very spirited driving, and I don't have to worry about blowing up axles. This stock TBI engine, pushes my Scrambler (4.10's, 33" tires, full hard top) effortlessly down the highway. It will cruise 80mph all day long, but only gets 14mpg. I am sure 70mph would see better MPG. I also run the 700R4 transmission.

The newer engine put out a lot more power, no doubt, but you pay to play, both monetarily, time wise on the swap, and "unforssen" future mods - i.e. axle swaps:twocents:
 

Randyzzz

Blown Budget
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Redmond
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OR
OK...put it on a trailer out to my place, and I'll get you taken care of. :D

Your costs on the LS conversion are too high, IMHO. There are a lot of variables. The LS can be made to play with the existing TH350. And, a truck LS has an engine driven fan that works great. There are places that will mod a junkyard harness for a lot less, look here: http://www.150tunes.com/ The reason I'm such a proponent of the LS engines is the efficiency and ease of tuning and modification.

The standard 350 is a good engine, IF you upgrade to TBI. I would never recommend a carb when fuel injection is an option. Finishing one in the shop now. Power is on par with a 5.3, maybe even a bit more bottom end. Fuel economy can be 15-18. I just don't care for the distributor/cap/rotor/wires setup when the LS is so easy being distributor-less.

Bottom line- if you're looking for the most economical, do-it-yourself solution, go with a junkyard TBI system on a rebuilt 350. The hardest part is the fuel pump, but a frame mounted pump will work.
 

hefavitzen

Scrambler Junkie
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City
Rock Hill
State
SC
Watch it Randy! I'll load it up and be there by Sunday if you aren't careful! I wish I could.

This has to be boring for most of you guys on here; watching someone flip flop on which way to go on an engine. I know a lot of you have been here as well. I feel like I keep asking the same question over and over again hoping for a different answer.

I have wondered about putting in a LM7 mated to the TH350 I have and driving it like that for now. I think I would have to do the motor mounts, wiring, cooling fan and fuel system. Then, as money became available over the next few years I could add the better transmission and axles. Is that nuts? Advanced Adapters sells a flex plate kit for $155. I spoke to Novak and they said, yes I can do it, but why would I want to. I spoke to Advanced and they said no, it won't work...even though they sell a flex plate kit to do just that.

I'd go with a TBI, but not sure where to get one. Carolina Auto Salvage has not got a good reputation and I'd like to smack the slackjawed face of whoever the nucklehead is that answers their phone.

I'd like to do this once or do it to last long enough that my wife doesn't say, "Didn't you just replace the engine?!?!?!"

I have only so much money and am wanting to get the best bang for the buck and honestly there are just too damn many choices. Let's put a hard budgetary cap at $5k, though I'd like to get it done for $4K for the whole thing if possible.

Maybe this thread should be called "Bang for the Buck - Where you can efficiently stick your 4/5K"

(I hope a budget number isn't inappropriate. Seems the best way to set expectations though.)
 

Randyzzz

Blown Budget
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Is there a U-Pull-It yard somewhere close? Look for a 1989/90 Chev pickup. Take the throttle body, wiring harness, distributor, any sensors that you can get out that are attached to the harness, the computer, and the complete intake manifold if you're feeling crazy. Any and all of the parts are readily available in the aftermarket. You'll also need a speed sensor and a fuel pump and lines. This is all aftermarket and I can get you sources. When you get your rebuilt 350 make sure it's a center bolt valve cover style. That way the TBI intake will bolt right up.

Read this : http://www.gearhead-efi.com/gm-ecm-pcm-conversion/tbi-efi-conversion.html

More links-


http://www.jagsthatrun.com/
http://chevythunder.com/gm_throttle_body_injection_pg_1.htm
 

LetchcoreCJ7

Legacy Registered User
City
Nashville
State
TN
The tbi 350 may not make huge hp numbers but the torque is about the same as a 5.3l. Still for $500 more the 5.3 seems worth it. Most of your expenses are in the parts not the motor.
 

cdvcj8

It's Not My Scrambler
Lifetime Member
City
West Friendship
State
MD
The only thing I can add to this discussion is that I have a wife like yours that wants to see me driving my/her Jeep :) To meet her criteria and yours it seems that spankrjs has giving you all the good reasons to get one from a junkyard or to go new with the ZZ4 and fuel injection.

I certainly would stay the heck away from anyone that is "going to figure it out" unless they are going to cap their labor costs (which won't happen). Otherwise it could get out of hand.

Finally, in regards to running 91 octane. It seems to me that 4000 / 15mpg * 20 cents more per gallon is $53 a year. Not that much of a burden :shrug:
 

mysunnshine

Legacy Registered User
City
Phoenix
State
AZ
Everyone knows my opinion already but here's another reason why...... The non-vortec 350 is already 19 years old at the newest. If you're going to make a change, it's time to update. Nobody surfs the internet on Windows 3.1 and a modem and enjoys it. The motors are about the same way and share about the same age too. For me it's ALL about driveability. I want at least 350 REAL hp and drive smooth. For a SBC to make 350hp, it'll need a camshaft to do that. Once you put the cam in, then the motor does not make vacuum. When a motor does not make vacuum, then your power brakes suck. Then you complain about the brakes and the "powerband" the motor has along with the poor bottom end performance. SO then you put a stall converter in it to help the low end performance. Now you have transmission fluid heating issues. See the trend? Stick the newer gen motor in it and go down the road.........They make power while they make vacuum with a stock efficient converter so they make mileage.
 

Randyzzz

Blown Budget
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Everyone knows my opinion already but here's another reason why...... The non-vortec 350 is already 19 years old at the newest. If you're going to make a change, it's time to update. Nobody surfs the internet on Windows 3.1 and a modem and enjoys it. The motors are about the same way and share about the same age too. For me it's ALL about driveability. I want at least 350 REAL hp and drive smooth. For a SBC to make 350hp, it'll need a camshaft to do that. Once you put the cam in, then the motor does not make vacuum. When a motor does not make vacuum, then your power brakes suck. Then you complain about the brakes and the "powerband" the motor has along with the poor bottom end performance. SO then you put a stall converter in it to help the low end performance. Now you have transmission fluid heating issues. See the trend? Stick the newer gen motor in it and go down the road.........They make power while they make vacuum with a stock efficient converter so they make mileage.

Well put.

If you end up going LS, I can steer you in some money-saving directions.
 

jbeemer

CJ-8 Member
Gold Member
City
Conklin
State
MI
Is your motor that bad? rebuild it, SBC are cheap to do. If it's decent, throw a tbi from the junkyard on and run it. then there's no exhaust, motor mount, radiator hose, steering hose......ect to deal with. And the tbi's are simple to hook up and there's plenty of places to burn a prom chip if needed.
 

hefavitzen

Scrambler Junkie
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Rock Hill
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SC
Is there any reason I cannot stick with the TH350 in my Jeep already and just put an LS, fuel and harness in? That ahold keep my cost spread out and I can swap in a new tranny, shafts and gears/axles later..........right??? I see muscle car guys doing this all over LS1TECH. Am I bonkers or blind?

Sent from my Nexus 7
 

mysunnshine

Legacy Registered User
City
Phoenix
State
AZ
You mean just put the LS motor in and run it with the T350?

Sent from my SCH-I545
 

MrBeep

CJ-8 Vendor Supporter
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CJ-8.com Vendor
City
Dillsboro
State
IN
Is there any reason I cannot stick with the TH350 in my Jeep already and just put an LS, fuel and harness in? That ahold keep my cost spread out and I can swap in a new tranny, shafts and gears/axles later..........right??? I see muscle car guys doing this all over LS1TECH. Am I bonkers or blind?

Sent from my Nexus 7

Congratulations! You now have a PLAN! :bacon: :headband: :wave:
 

mysunnshine

Legacy Registered User
City
Phoenix
State
AZ
Absolutely. The problem is that you need keep in mind other changes with a trans change later on.

Sent from my SCH-I545
 

hefavitzen

Scrambler Junkie
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City
Rock Hill
State
SC
Well this works then. When I told my wife the estimated cost of the whole shebang I could see the dream of a winter vacation at a beach somewhere die in her eyes and her inner voice telling her to remain calm. This would allow me to proceed somewhat under the radar...building up to the finished product.

Sent from my LG-E970
 
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