[monster76]

Go for it but if it were id go for the 6.0 lq4 from the truck or the lq9 6.0 from the escalade.they have more power and same work to install

[ap72]

Originally Posted by monster76

Go for it but if it were id go for the 6.0 lq4 from the truck or the lq9 6.0 from the escalade.they have more power and same work to install

and cost 4 times as much...

If you shop around you can pick up a 5.3l for $400. If you find a 6.0L for less than a grand its a miracle.

[E.Furgal]

400 bones, good luck..

[ap72]

Originally Posted by E.Furgal

400 bones, good luck..

I don't know where you're from but around here they commonly sell for $400 from a junk yard- of course that doesn't include the harness or ECU, that's usually another $100.

I just pull all the pig tail connectors I need and make my own harness, IMO its a lot easier and it gives a cleaner install.

[AutoGear]

Its not hard to put a Muncie behind an LS motor; and a Luk Repset clutch is absolutely fine for what you're doing. Best thing you can do is figure out which Muncie you have; Ive posted it all before, or just PM me. If its an M21 or M22; You'll want a 3.73 rear to get your tank moving. At that point you may be better off selling it and saving your pennies. If you're mechanically inclined and have a shop press, you may want to disassemble the trans. If its a stuck pig, planning your build around it will take on another $5-700 easily. I'd say the best bet for you is an M20 (2.52 1st gear), but you're still going to want something like a 3.23 or more rear gear. There is a 2.98:1 1st gear M22 gearset (aftermarket only), you could run 3.08s happily but between that and an overhaul kit, you'll be in it almost a grand in short order (you'll probably need forks, mainshaft reverse, the splined reverse idler and I'd definitely pop for an iron midplate). This is assuming the countershaft bore hasn't had a cobb-job to keep it from leaking.

I love 4 speeds; but Ive seen a lot of junkers and I want you to be realistic. Nothing worse than planning around something, muscling it into place and finding out it in sad shape. Then you gotta tear it out, find the money, fix it and shotgun it back in there.

BTW the Z-bar is the way to go. A lot of hydraulic setups in the aftermarket just don't seem to last long, or work as expected.

[bigdog7373]

Thanks for all the responses guys you're all a lot of help. I'm not buying anything until i get the tranny checked out to make sure it's in good shape. I got it for cheap out of a driving car so i'm not too worried. I believe its an m20 but i'll find out for sure. Around here it's not unheard of to get the motor for $350. They are all over the junk yards in wrecked trucks. I'm going to grab the computer and harness with it and modify the harness for what i need. Doesnt seem like too bad of a job, plus i'll save a lot of money over an aftermarket piece. I dont want the 6.0 cause they are expensive and it would kind of defeat the purpose of the swap since i'm really wanting more mpg's so i can drive it more.
If the 4 speed isn't in as good shape as it seems then i might get the trans with the motor. But i'm hoping that's not the case and i can have the 4 speed i want.
I'm not doing anything with it til the summer but i like to plan ahead so i can get an accurate parts list and get the swap done trouble free instead of having to gather parts with the engine half way in the car. I hate working like that.
I'm not too worried about how fast the car will be, i just want something that i can take on the highway comfortably without it revving sky high or anything. So i guess i'll have to do some more thinking about what i want to use for the transmission. I can always sell the muncie for what i bought it for and come out even. Plus i still have the running small block and the th350. If i were to sell the current engine/tranny i could easily pay for at least half the cost of the swap.
I really want to modernize the car without losing the classic look. I got some bmw e46 seats planned for the interior, all new gauges, vintage air a/c, keyless entry system, the works. Only thing holding me back is school

Any more advice about the swap i'd really appreciate. Thanks!

[ap72]

If you're just wanting to get good mileage and decent power a TPI 305 with a T5 will get you suprisingly good mileage, and with a few little parts can get over 300hp. I picked up a chevy WC T5 for $200 about a month ago, freshly rebuilt too.

A well build gen1 sbc can get good mileage, but it will never be the Gen III/IV stuff.

If you're really after mileage you either need an OD trans or need to swap the rear gears. Drop your highway cruise speed to right under 2,000 will make a huge difference.

LS swaps have a lot of potential, but they do cost more than swapping in a different gen 1 sbc- if cost is a major factor (which it sounds like) then you may want to explore other options.

an LT1 is a great in between compromise, as is a Vortec enigne with a intake swap (thought going MPFI is more expensive going this route).

[bigdog7373]

Originally Posted by ap72

If you're just wanting to get good mileage and decent power a TPI 305 with a T5 will get you suprisingly good mileage, and with a few little parts can get over 300hp. I picked up a chevy WC T5 for $200 about a month ago, freshly rebuilt too.

A well build gen1 sbc can get good mileage, but it will never be the Gen III/IV stuff.

If you're really after mileage you either need an OD trans or need to swap the rear gears. Drop your highway cruise speed to right under 2,000 will make a huge difference.

LS swaps have a lot of potential, but they do cost more than swapping in a different gen 1 sbc- if cost is a major factor (which it sounds like) then you may want to explore other options.

an LT1 is a great in between compromise, as is a Vortec enigne with a intake swap (thought going MPFI is more expensive going this route).

I definitely want as ls engine. I had the 5.3 in my tahoe and they are really awesome motors. Smooth as hell, good power, good mileage. I want to get the car up to the 21st century, get away from the usual small block chevy that everyone and their mother has. I want to keep costs as low as possible but i don't have a problem with spending money. To me it's not worth upgrading to anything else because i know i would regret it in the future.

The 5.3 is a go. I'm really just down to deciding on a transmission. Is the 4 speed going to hold me back? I want good mpg and highway drivability but i don't want it to be a slow pig. With the 4l60e that comes on the 5.3's i know i will have the benefit of overdrive but i dont want it to be boring to drive. I really enjoy shifting actually and i dont want to get bored of the auto.

[E.Furgal]

Originally Posted by ap72

I don't know where you're from but around here they commonly sell for $400 from a junk yard- of course that doesn't include the harness or ECU, that's usually another $100.

I just pull all the pig tail connectors I need and make my own harness, IMO its a lot easier and it gives a cleaner install.

here 400 bones will get you the engine ONLY.. no front dress, no starter, a cut harness,

5.3's low miles 90k and under 700-800 all day

[bigdog7373]

Originally Posted by E.Furgal

here 400 bones will get you the engine ONLY.. no front dress, no starter, a cut harness,

5.3's low miles 90k and under 700-800 all day

Come on. Are you seriously going to argue about price? Stop. I dont care how much what costs where. I just want to plan out the swap and worry about price later when it comes to actually buying the parts.

[starnest]

I'm a big fan of ls engines, a couple years ago I traded my 5pd, 4cyl Cherokee for an 04 gto w/m6. The Cherokee managed about 19/23 mpg, the gto with careful driving can manage a decent 19/26 mpg. Not that it matters, because the way I drive it yields much less. But I drive less than 10k miles a year so I fund the difference as "entertainment".

The swap, if well planned and executed, could provide a great improvement for your Firebird project. But, is it worth it?

To do this right we need to know how much you drive, before and after estimates of mpg, average price of gas, and what the swap really costs. I don't propose to argue the fine details of each parameter, instead I propose an example you can use to do your own calculations.

In my example, I assume you drive 10k miles a year, the bird is nailing down 15 mpg now and after the swap (using your 4spd as is, and with optimum tune, gearing, etc) you manage 20mpg (a 30% increase). I'll use the good gas at $4/gal; and expect to complete the swap for $1500 (low end estimate IMHO).

Monthly savings equals milesdriven*mpgafter/mpgbefore*price/12=10000*20/15*4/12=$55/mo
or
So before the swap you spent 10000/15*4=$2667/yr or $222/mo on gas.
After the swap you'll spend 10000/20*4=$2000/yr or $167/mo on gas.
222-167=55 (Notice the 30% savings in cost)

With savings of $667/yr or $55/mo, it'll take more than 27 months ($1500/55) to break even. While $55/mo isn't a fortune, it is worthy of consideration.

Of course you can change the assumptions used and get a very different result. Keep in mind the calculation is only useful if your assumptions and estimates are correct.

Now let's look at how changing the assumptions affect the outcome:

miles per year - double the miles, double the savings and cut time to recover cost in half (keep in mind though that double the miles also means double the total cost of gas).

ratio of mpg before/after - increasing this parameter is the heart of the matter, resulting in more savngs to match the improvement realized in mpg (again, keep in mind to achieve more improvement, expect to spend more on the swap)

price of gas - as prices go up your savings increase (the inverse ain't happening, don't get me started)

cost of the swap - increasing cost of the swap increases the time to recover your investment (this parameter is the most difficult to get right and the impact can be huge)

So is it worth it?
Put your own numbers in the calculation and you'll know (as long as you are honest with yourself, and not dreaming of going from 15mpg to 30mpg after a $1000 swap).

A few other factors to consider:
seat of the pants thrill an ls can provide
satisfaction from being smarter than the average bear (thx Yogi)
satisfaction of a job well done
pain and anguish of an unfinished project because of time, money, etc

[bigdog7373]

Wow thanks! In my case the swap will pay itself off rather quickly. I have to use 89 octane in my current setup because of compression, so that's 25 cents per gallon more than the ls engine which i could run 87 in. I'd estimate 10k miles per year, is about right. Also in the car's current form I average about 12 mpg. So:
Now:
10,000/12=833 gallons@ $3.90 per gallon = $3248 per year.

Ls:
10,000/20=500 gallons @ $3.65 per gallon = $1825 per year.

That's a $1400 savings per year. So it will just about pay for itself in a years time, but wait there's more
Lets say i get $600 for the engine and trans i have. Well now the swap only costs $900 out of pocket. So if i do this swap this summer then by next summer i would have actually SAVED $500 over not doing the swap. Well what the hell am i waiting for?! Wow I'm excited now

[vinniekq2]

buy a little toyota and drive the sports car in the summer time.Make the sports car a lot nicer so you can actually show off.

[bigdog7373]

Originally Posted by vinniekq2

buy a little toyota and drive the sports car in the summer time.Make the sports car a lot nicer so you can actually show off.

I only can have one car since i'm in college. I'm collecting all the parts now so i can get it done pretty quickly this summer. I'm pretty excited. I'm building it exactly how i want it. A nice combination of old and new.

[ap72]

Originally Posted by bigdog7373

Wow thanks! In my case the swap will pay itself off rather quickly. I have to use 89 octane in my current setup because of compression, so that's 25 cents per gallon more than the ls engine which i could run 87 in. I'd estimate 10k miles per year, is about right. Also in the car's current form I average about 12 mpg. So:
Now:
10,000/12=833 gallons@ $3.90 per gallon = $3248 per year.

Ls:
10,000/20=500 gallons @ $3.65 per gallon = $1825 per year.

That's a $1400 savings per year. So it will just about pay for itself in a years time, but wait there's more
Lets say i get $600 for the engine and trans i have. Well now the swap only costs $900 out of pocket. So if i do this swap this summer then by next summer i would have actually SAVED $500 over not doing the swap. Well what the hell am i waiting for?! Wow I'm excited now

$600? You must have the midas touch. a worn 350/th350 is worth slightly more than the price of scrap around here, maybe $300-$400. BE REALISTIC. your mileage and gas prices seem accurate though. $1500 for an engine and trans swap seems low to me, but entirely possible. you may want to figure an even 2 grand- so you'll pay it off in about 2 years (still not bad!)