I would like to build a 5.3 Ls block that I have acquired for around $200, it is missing the accessories, harness and the PCM. My main goal just as many other people is to have a budgeted build for less than 3.5k. Ultimately I would prefer to get the block in by the end of next summer (2023) because college is on the horizon and saving gas money and being cool at the same time would be awesome. I picked up a 5.3 intake with the fuel rails and injectors for $50 and then the ignition coils for $50 as well. I have 2 sets of 706 heads that came with the block and I have all of the stock internals.

The block has just barely any surface rust in the bores and my first question is how could I clean this and still have an ok or good cross-hatch? The pistons do need carbon cleaned off and I was wondering what would best do this?

My second question is what would be some cheap upgrades to make? Just a simple Camshaft and springs set? Or should I just simply wait to make upgrades and do it later on?

I am also wondering where should I get many of my parts? I understand bearings and such should be bought new off of summit racing and such but can't I just get almost all of the accessories from a junkyard? When the cars crashed their components were still working hypothetically so?

Now I have a 79 Firebird so that means a BOP th350. I believe I can just get an adapter plate and call it a day no? I also understand I need a spacer because I have the flexplate that has the divot and a new Torque converter.

And the biggest question I have is about the PCM and wiring harness. This seems to be the hugest chunk of my budget no matter where I look. What is the cheapest PCM and Harness to get for an LS that is specific for a 5.3 LS and a th350. I have been looking and I understand that an older transmission (th350, th400 and 700r4) can be compatible with a t56 tuned PCM because they act on their own.

I believe I can do this from engine, to transmission to everything else for ~$3,600 any way to cut this budget would be huge and any recommendations are 100% appreciated.

 

If I read this correctly

-you have a '79 firebird
-you want to LS swap it for < 3600

this is not only possible, but fairly easy if you're patient and careful.
My swap was a '98 volvo station wagon. Completely un-GM. I purchased most of a '99 z28 camaro, which included the engine and transmission, for $1700. This gave me a running and driving donor.

I would highly suggest you swap to a 4L60e or 4L80e transmission. It'll be way better.
As far as your budget, I would try to buy a running long block or complete motor instead of rebuilding what you have. If you have surface rust in the bores, they likely need a few thousandths shaved off, which means you're buying new pistons. $$$. I recently purchased a running 5.3 L59, which included the harness, accessories, computer, intake, injectors, etc, for $500. It took some patience to find but they are out there.

as far as upgrades, knowing what i know now i'd do a 5.3 (preferably L59 because the injectors are bigger) - 500
i'd stick a new oil pump in there - summit sells the melling 10295 for like 75 bucks, cheap insurance
grab a trailblazer stall converter from the boneyard - best factory stall, about 2600 rpm - 75
truck norris cam - 400
the cam will require a valve spring upgrade (LS6 springs) which you should do anyways - 100
4L60e - should be able to find one for < 750
shift kit including upgraded servo - 200
you'll need an oil pan that fits - i would google "poor man motorsports". They sell 81075, 81074 one of which might fit what you have. You could also see if a stock pan like a truck oil pan, hummer H3 oil pan (GM calls this the "muscle car" pan), fbody, etc, might fit.
TBSS intake - $100
tune - 250
then you still need to figure out driveshaft, exhaust, etc. If some set of long tubes from ebay fit, good riddance - 200. then you'll need a header back exhaust, figure 400. or they could connect the headers up to your factory exhaust.
driveshaft - maybe the factory one can be shortened and a new yoke put on it - 250
then you need a fuel system. This could be tricky since the car probably didn't have EFI from the factory. Not sure what it would cost to convert such a system.
you'll also need an intake and cooling system. you can probably use 4th gen fbody components and make them fit. would highly recommend running a surge tank as the self-de-aeration makes the cooling work much better. would also highly recommend running e fans.

in any case, this setup should get you about 400 flywheel HP, really good drivability, and the improved fuel economy and tuning capability that comes from an overdrive transmission. all in all, i'm sure you can make it run and drive for < 3k. the boneyard is your friend for bits and bobs. fuse panels, wiring, etc etc.

hope that helps!!

 

Yes this does help a lot, I will take all said into consideration thank you very much for your time

 

Kyle, be weary of "doing it cheap, and doing it right." When you're on a very tight budget, cheap parts can make a ton of sense, that is until they don't work or fit right. Junkyard stuff is getting harder and harder to find deals on since the LS cat is out of the bag. I paid 700 for a LM7 with no accessories or wiring six months ago, that that was "cheap."



"summit sells the melling 10295 for like 75 bucks". I read this and was like, yea, no way that's possible. .

Summit Melling 10295 $138.86

 

https://www.summitracing.com/parts/s...4aAno8EALw_wcB

as far as price for a motor, i think it really depends on what's available in your area and how patient you can be. I've been able to find multiple 5.3 pullouts (south carolina, north carolina, atlanta, alabama, etc) within a 4 hour drive for about $500 with everything. But it does take some time.

 

Good call, the Summit 10295 "ish" oil pump is 75 bucks, not the Melling.

 

The pump you quote is Summit's own stock-spec pump. Not high pressure like the Melling 10295.

 

You can get a cheap harness from ebay and a stock PCM from the wrecking yard, but without Hp tuners you wont be able to tune the car at all.
So
Ebay harness $250
junkyard PCm $50
unlock PCm with credits $100
Hp tuners $400
Wideband $200
So thats a total of about $1000 to use the stock ECM and dont forget to add LOTS AND LOTS of hours to learn how to tune it yourself.... This is the route I took and I regret it every day lol
Unless you just keep it completely stock then you just need a vats deleted PCM
You can also disregard buying Hptuners and just pay someone to tune it every time you change the setup but thats not cheap either.

Holley terminator is around $1300 and is MUCH more user friendly.

I did a VERY VERY budget swap into my 72 firebird and you can certainly do it for around your budget.

 

tunerpro - free
use the 2002 OS, which is well supported and has XDF's available on gearhead-efi - free
obdx pro vt - $75 - this is the hardware required to write to an 0411 ECM
pcmhammer - free - this is the software used to write to the ECM
pcmlogger - free - this is the software you can use to log
wideband O2 - $200 or so
boneyard ECM - $50 - 0411's are easy to find
boneyard harness - $30 - that's what they charge around here anyways

this is how I tune. Its not as clean, fast, or versatile as HP tuners, but for gen 3 stuff its definitely cost effective. especially if you're just disabling VATS and changing the shift points around to run an essentially stock motor in a swap vehicle.

edit: DEFINITELY not trying to discount your input, as for more serious swaps with aftermarket parts making lots of power, aftermarket self learning systems start to become much more cost effective. however for somebody looking to swap a basically stock motor with simple mods like bolt ons or small cam, the factory ecu can be a cost effective way to get you on the road.

 

NICE!, I used to use tunerpro for my LT1 stuff but its been a LOOOONG time, I had no idea you could even do the LS stuff with it.
Although without a good tutorial id be clueless on what to do lol

 

Just thought about this, would I need to get a new gauge cluster?

 

A set of Dakota Digital gauges will make this easier but you should go to the Dakota Digital web site to see if their adapters can do a little magic for you.

Rick

 

All your gauges are mechanical and you can waily just reuse them. Although the cheapest setup would be to use a digital dash that plugs into your OBD port off Amazon or ebay. The Dakota digital stuff is great I’m sure but that would be a huge portion of your budget.

 

Here's the $31 OBD-II gauge cluster I use from Amazon. It plugs into the OBD-II port, and is mounted to the steering column with double-sided tape.