So, I’ve done a lot of research before coming here and I’ve realized the simple “what engine is best” is a big no no around here so here’s what I want and my budget.

I Have a 89 iroc z28 I want it to be my daily driver and to be able to get about 375+ hp out of it. I’ve seen the LS swap and it looks enticing but I’m curious about other options. Is it possible with a 350? I see a lot of post saying that it’s not hard to get that horsepower but not many that also include being able to do this to be a daily driver. I’m in Oklahoma which currently has no swap regulations and do not require emissions testing. I have about a 5000 dollar budget but if I’m sure I’ll have to break that budget and I’m somewhat ok with that (my wife won’t be) ¯\_(ツ)_/¯

 

Well here it comes, LOL.

Welcome! IMHO, anytime someone asks us that question with the constraints, it's a fair question and I'm happy to help out. $5,000, daily driver, 375+.

A few questions...

First and most important- Do you love your wife? If "Yes, but...", then stop here. If you're not sure, then proceed.

Is it the stock L98 350 (5.7L)?

Auto or Stick? Do you want to change the trans also in this budget? If not, what trans is in there now?

 

She’s actually understanding and knows that I’ve been putting off for a while, plus it’s easier to ask for forgiveness than permission.

its a stock 4L60E 5.7 I’m willing to change the trans if necessary I doubt that would be included in the budget though

 

Speed = Cubic Inches X Cubic Dollars , Squared ...

Oh , and one small correction , if it's a 1989 IROC you have a 700R4 . It wasn't renamed as the 4L60 until sometime in the 1990s and didn't become the 4L60E until it got electronic (PCM) control of the shifting .

 

you will need forced induction or high revs with a fully reworked engine and intake system to get a real 375 street horsepower...Reduce the goal to ~320-350 HP and you are back in the "bolt ons"realm-different intake,head upgrade,exhaust upgrade,cam, and you are there with turn key reliability and good daily driver manners.

 

I run a 400hp engine on my 79 daily driver N/A. It’s a 355, forged bottom end flat top pistons, sportsman 2 heads, with a z35 cam (isky 201035), Edelbrock performer and a modded holly 4150, 1 5/8 headers, high volume fuel pump, Petronix flame thrower v3 etc. built th350 for 600hp, 2k stall. Stock driveshaft stock diff stock everything else. You are correct about the hp being on the high end but isn’t that what we want on a dd? I can get decent (still garbage) mpg if I drive it normal and keep the rpms down. In 2, almost 3 this spring, I’ve never been left stranded and the car has never not started = mint daily bro.

I hate when people say full bolt ons out in the real world when asking what all they have done lol.

ive spent more than 5k I think, but I don’t look at receipts it hurts

 

Getting 375 reliable, daily-driver-streetable hp from a small block will require more cubic inches; think, 383 or even 406, and with an aftermarket fuel management system to eliminate all the shortcomings of carburetors and attempts to use the 30-year-old 3rd gen systems. More cubes allows you to be more conservative on compression and cam specs which results in a package that will be more suitable for stoplights and every-day traffic situations.

Personally, if your goal were mine, I'd forego the small block and roll with an LS swap. A good junkyard 5.3 with little more than a cam change will put you right in the picture---no pain/no strain---with dead-nuts reliability, good streetability/gas mileage, and way below your $5K budget.

 

probably also commenting on if its something you'd be pretty hands on with or looking for a turnkey option

For flywheel horsepower, a build like the one I've in perpetual progress could be an option:
GM L31R longblock
LT4 Hot cam - springs/ locks etc. to handle the lift and think about getting screw in stud (though I haven't)
suitable vortec intake. You do see some used superam's (with vortec bolt pattern) which would've been my preference but ended up going with an Edelbrock pro-flo XT (more expensive, more custom, may not clear stock and performance tbc)
decent sized injectors (Ive gone 30lb)
tuning gear. I got a EBL P4 on here for a reasonable price. Makes tuning easier but still requires homework. Strongly recommend a Wideband o2 sensor

a few good posts on here about L31/ Hot-Cam installs

I've seen HP claims in the 350-400 flywheel with this and buying used and not buying twice (the wrong stuff, making a dogs dinner of fitting and ruining parts) can be done for well under 5k I'd say.

 

If only there were a few dozen (hundreds) threads discussing possible engine replacements for every possible goal and contingency...

 

if nobody answers questions the forum will be dead/die.

 

375 flywheel is easy

375 whp is also easy but will cost more.
IF your 5.7 is in good shape, heads cam intake can get you there.

think afr 195’s or equal, 280xfi cam, miniram/stealth ram/single plane efi if goin efi

 

The days of hotrodding a sbc unless it's for a period correct look of you already own good parts are behind us. A pair of assembled and ready to run AFR heads will run you $1500. Exhaust will be another $500, at least. The intake and injectors and throttle body setup will run you $1000-2000 depending on which intake. A cam will be another $300. A tunable efi setup will be $300-1000. I doubt you would get more than 350 wheel HP while still being streetable for a daily driver.

Do a truck engine LS route with the automatic. Take your time. Read everything you can on these boards about it. There is enough information already posted about it to answer every question you could ask. Cam, exhaust and tuning software $1000-1500. Junkyard 5.3 with tranny $300-800. Yeah there will be plenty of other swap parts that add up but the LS will make more power with less work and money while having better street manners.

 

And with the 5.3 route you now have an engine you know nothing about. No idea where it’s been or what it’s been through that can fail the day you put it in. Same goes for the transmission. If you dig into an LS based engine it WILL cost more than a sbc In the end. You don’t need EFI on a daily driver if you actually know how to drive a carbed car.

The SBC will never die because of how easy they are!

 

You must've had your head buried in the sand for the last five years. There are an innumerable amount of message board builds, magazine builds, YouTube builds, company builds and racing series builds that are using a 4.8/5.3 truck engine with unknown mileage making big power (for the street) dependably. One build I recently read was a 23X,000 mile truck engine, zero problems. If you do the wiring and fuel plumbing yourself the swap is no longer big money. If you can weld the swap is cheap, dare I say cheaper than the machining and gaskets and replacement parts associated with rebuilding a sbc.

 

lol I'm in the same boat with this question and my wife is like are you going to do anything to up the power in that car? lol she is 50 years old too...a little younger :-) but is spoiled from driving other cars and trucks we have owned. However she loves the looks of the Thirdgen and so people compliment on it.

Anyway I got a quote from TPIS, they will do a complete drop in motor for $7900 with a tune for the specific setup. Their Mini Ram'd 350 4 bolt main, heads & cam, drop in motor makes 450-460bhp per their email to me. When I add everything up it seems pretty reasonable. It doesn't include headers or a fuel pump though.

 

seems steep depending on parts and labor

 

Here is a list of a few LS swapped thirdgens. Looks like a mildly cammed 5.3L will get you where you want to be.

https://www.thirdgen.org/forums/ltx-...o-results.html

 

It does. But it's a pretty stout block having a 4 bolt main, forged pistons, rods, Callies Dragonslayer Crank, etc. Miniram alone is $1K. Seems like when all is said and done you don't have to rewire or buy an LSx harness, plus crossmember, or new tranny. Just motor a motor swap and probably add a 2400-2600 stall converter. The highest I had my first (97' C5) LS1 was 430 rwhp with just H&C. (M6 tranny). So LSx is still going to be superior for making power...plus has 6 bolt main. I put down 850 rwhp with a forged LS6 (stock crank) Twin Turbo but ran it at 600rwhp and 91 octane for 12K miles before I sold it. The leak down test showed that the motor was still holding up great.

There just seems to be a lot more to an LSx swap as it takes the motor, harness, fuel tank/pump, tranny, plus has to be the correct accessory config to keep AC. I would have to price it out. I will have the blower off my LT4 Z06 soon so that I can install the Maggie 2650 that I picked up. It has crossed my mind to pick up an LT1 and use my LT4 blower as a swap. But it all seems like such a hassle lol.

 

If my opinion counts at all...I'd say 6.0L lq9 swap. Mild bolt ons (msd coils, wires, plugs, intake, exhaust and a good tune) should get you close to the 340-350 area.

If I had my time back, I would have gone that route as opposed to dropping 8 grand on a 355 build that only makes 320 whp.

My builder did a 6.0 swap in his ws6 with the few items mentioned above and made 346 whp and 337 two after a tune.

I would have spent about the same to ls swap mine but in the interest of keeping it simple I opted the SBC route and have been kicking myself since.

 

I had a lot of friends using the lq9s back in the day 2002-2004 in their C5s because of the iron block for 408cid builds. They were also running lots of boost and NOS. They were all great builds, but I didn't like the fact that the iron blocks added additional weight up front on a car that was balanced 51/49 (c5) front to rear. I would opt for an all aluminum block over an iron block.

I think it comes down to a fundamental question does one want to have an pseudo period correct motor in a Thirdgen (modified SBC that uses an intake other than TPI) or an LS swap ThirdGen that is really nothing more than a resto mod.

I can certainly appreciate your opinion and perspective as I had to go through this recently with my 66' Mustang restore, I went back and forth for a year deciding whether to do a 306/347cid or a COYOTE swap. I decided to keep the SBF ($5K forged 306 roller with AFR heads etc) and then the dilemma was whether to go EFI or stay with Carb. I ended up with a 400hp carb setup. When people want to see it I pop the hood and it looks good as it still looks like a SBF Windsor, but I think how cool it would have been to have a COYOTE swap too that makes 425hp and gets 24-26 mpg (not really a huge factor but nice). Now I have a 400hp SBF where I can watch the needle on the gas guage go down as I'm driving it lol.

 

If you ask that kind of a question on a forum like this, you won't know what to do with the responses you get. Anyone who tells you that a swap to LS in a 3rd gen is cheaper, is blowing smoke. Swaps are not inexpensive, and if you're gonna go that route, you need to FIRST cost the swap separately BEFORE you start to cost the powerplant. For those who can do it themselves, it costs TIME, which you must have available. If you cant do it yourself, time COSTS, a lot. The reason many people with this generation of car stay with the engine it came with is that it was designed with it, and adding modest amounts of power to an existing design is cheaper, because it takes much less time.
If you want to make big horsepower, after the swap is done you can get it done cheaper over the long haul with a LS, depending on what you ask for. Generally, horsepower costs big bucks, and we're talking 5 figures, not 4, LS or otherwise. If you talk to a knowledgeable small block engine builder, you will find out that 350 HP really isn't that hard if you know exactly what to use, original or LS. Remember that 350 hp is really more like 450 hp, if you want it to work like 350. Biggest problem is people always start out with realistic goals, then as they build, 50 extra horsepower really doesn't cost that much, but fail to consider that 50 horsepower gain can only be realized by changing the package it comes in, that a cam by itself doesn't make that 50 hp.....
I don't think the question here was are LS engines better or preferable than original smallblocks, the question was 'can $5000=375hp?'

IMO, if the short block in the car has to be changed out or rebuilt, you can't make 375hp from $5000

 

These cars were not blessed with strong parts. You guys know how it is, go above a certain power level and the crappy stock drivetrain blows up. So is 375+ Hp under that threshold? Answer honest.... the OP is depending on you.

And no matter what, you're doing all the same mods of exhaust, fuel, brakes, suspension, blah blah blah. Burn chips to tune your engine? Don't make me laugh. There's a modern EFI conversion coming with this build sooner or later.

What you're not doing with the LS is tearing the whole thing up to make 375+ Hp. That's called bone stock, or just a cam. And you get a fancy dancy ECM controlled transmission with it. Pretty neat stuff.

But no doubt about it.... playing with cars is a dark hole of losing money. And I personally don't consider a 3rd gen a good daily driver. They aren't great cars. But they can be fun and that's a reason for driving too.

 

Here is the 1/4 mile list. Not very many examples, but you can kind of get a feel for when people changed out parts to go faster.

https://www.thirdgen.org/forums/orga...92-f-body.html

 

well you have fun with your shabby wiring, 200k engines with ****ed bearings & rings, and bugger welds.

I read that pigs can fly!

 

If you have the means to remove and disassemble your engine and then the money to pay a shop the machining costs and then the knowledge to know what to order to rebuild the engine then you have the capacity to do an LS swap. At this point an LS swap has become paint by numbers with all the info in this website.
LS engines are cheap and plentiful. $170 will get you an engine with accessories in the yards by me. Rotate the crankshaft with a breaker bar and do a leakdown test to rule out any large issues and run it.
Check out videos from sloppy mechanics and driveway engineer for how to do the swap simply and inexpensively. They also go over proven power combos.

OR sink thousands of dollars into your sbc 350 and just be content if you make over 300 rwhp

 

Once bitten twice shy
theres a lot on unscrupulous people out there and the ‘I did a LS swap for 500 $’, ‘million miles and looks brand-new’ rhetoric makes people assume all used engines are good and sellers trustworthy

new for new, gen1’s are cheaper for most mild power applications. And the challenge for most driveway hobbyists (me included) of getting an engine makes it something they’d only want to do once