I have a 91 RS Convertible that I picked up because I wrecked my 91 Hardtop. I bought a TPI with harness and CPU and have a rebuilt 5.7...

A friend of mine has a LQ4 out of a 02 Suburban w/only 16k miles on it... He wanted a grand for it but a month later I called him and he said take it away for 500 bux! That was yesterday...

I was planning on a 383 TPI, but now I am thinking of going with the LQ4 and buying LS6 heads and intake/throttle body to raise the compression. I also want to put a pretty aggressive cam in it(but streetable), I am also going with automatic will be going with the 4L60e.

I did a rough parts list and for me to have the LQ4 in with me and my buddy installing would be around 3 grand and would probably have around 425hp (guessing)with Cam and heads including the trans... and for me to get even close to that with a TPI is around 4500...(400-450hp)

Does anyone have any suggestions?

 

Yeah. Do it and thank me later

 

cool! well if you have any info on any snags you came accross, maybe things I should look out for?

 

If the LQ4 has the "317" casting heads you might as well keep them as they flow just as well as the LS6 heads, you just lose a small amount of compression.

 

I will be looking at it again tonight so I will make sure of that... Thanks for the info!

 

I would think the HP estimate high and the cost estimate low. But, that's just from experience.

cam- is probably still right.

You did read the LSx swap sticky, right?

 

Yeah I did, I am going to go over it again... My estimate was very rough, I didnt really include any suspension, and did not include headers, and this in the assumption that I can figure out the wiring myself...

 

what about l92 heads? since you're going to have to buy a new intake anyway. Pretty sure they flow better than ls6 heads.

 

The reason I was looking at LS6 heads was to bump up the compression, I have not looked into the L92 heads, would they raise compression also?

 

The L92 heads are 70cc heads. So compression will stay roughly the same. I think it was car craft (or one of the mags) That put l92heads and l76 intake on with a diff cam and headers with diff programing and made like 549hp. Kinda nuts..

 

I remember that there was a guy on LS1Tech that cc'd a set of L92 heads & found that they were right at 68cc. Either way, they're right in that ballpark. One of the things that I'm learning about these engines is that they seem to like a good compression ratio, so I'm giving serious thought to milling my L92s down to give me about 64cc...

Of course that would ultimately limit any forced induction plans down the road, but hell, these things are cheap enough that it wouldn't hurt too much to just buy another pair...!

 

THe LS6 heads are for a 5.7 and the LQ4 is a 6.0 I'm fairly sure they won't fit. Check out performancetrucks.net for lots of 6.0 info though!

 

Thats strange... I have read that all LSx heads are interchangeable with all LSx blocks...
The LQ4 block is just a Cast LS2 block, and I believe you can use parts between LS2 and LS1 and therefore LS6 also.

 

Oh and I was way off on what I'll be spending to do the swap...
Here is my list:

LQ4 - $500
LS6 Heads - $1000
Cam - $300
4L60e - $1000
LS6 Intake - $300
Motor Mounts & Trans X-member - $200
Fuel Pressure Regulator - $160
Fuel Pump - $100
Front Accessories (estimate) - $350
Oil Pan - $150
Throttle Cable - $60
Fuel Lines to Regulator - $250

TOTAL:$4370

Not including Exhaust... I am going to have a y-pipe made for now, as I can't afford the 800 headers from hawks just yet. But when I do the exhaust I want to run true dual, so I'll have to get the new panhard bar and I want the electric cutouts also .

I also need a new top and SFC's and paint. But when this thing is done I am sure I will be happy... I keep telling myself I am not repairing it, but rather rebuilding it...

Oh by the way I have a 5.7 with about 30k miles on rebuild, and complete TPI setup with ecm/complete harness, and everything one needs to swapo from auto to t-5 including the t-5, pedals, new slave cylinder, master cylinder, resevior, shifter, and center console shift boot (no cracks or holes)... Anyone know how much I should get for that if I sell it?

 

LS6 heads will work, because I have them on my LQ4 6.0.

 

Awesome!! Have you dynoed it or taken it to the track? What is your compression like?

 

Man, my car has been in the shop forever so I don't have any kind of numbers. I have been wondering what I would get out of it myself. I read on LS1tech somewhere where the compression would be either 10:5 or 11:5 or something around that I can't even remember but it was pretty good

 

Cool, that is what I am hoping for... Let me know if you have any updates

 

Reality bites, eh?

But, hey, the reward awaits you. . .

 

Yeah, I can't wait... I'm picking up the LQ4 tomorrow
I have made up my mind to do the swap! I hope it goes smooth!

 

Just picked it up and pulled the intake and exhaust manifolds, and cleaned it all up... I already like working on this much better

 

You know the headachs begin when you go to drop it in. Always works out that way..LOL Keep us posted and take some pics! Looking to do a swap in the near future!

 

Al in your perspective I guess. Driving them is satisfying sure. But the real fun is in the build

Good luck Jonny!!!

 

Here is the LQ4, has the iron heads, gonna have to fix that.


Cleaned it up a bit


Took off the intake, exhaust manifolds, still need to take the heads off.

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Here is my old 91 RS that this engine was planned for... (Hydroplaned on the freeway and totaled it).


Here is the best pic I have of the new 91 Vert.

 

Anybody got ne ideas for heads, my two main choices are going to be the 243 ls6 heads with the 64cc chambers, i think, or the dart pro heads 62cc chambers 225cc runners. Alot of people suggest the l92 heads but i am looking to raise the compression, due to the lq4's dished pistons. I have seen the patriot 59ccs but thats lookin at alot of money, and im looking at pullin 400 at the wheels. Also any cam suggestions? Id figure id call comp and ask them too. Thanks everyone

 

Well, I'll just tell you what I've found, & you can use the info to make your own decision...

It seems that if you buy a set of bare L92s, the total cost (inc. the heads) once you install valves & all the other hardware is going to be about $850. (Based on a number of LS1Tech posts I've seen.)

I already have a set of bare L92s, & I've been giving serious thought to bumping the compression up, so I called a local machine shop how much it'd cost to knock about .030" or .035" off, as that seems to be what's required to get 64cc chambers. I was quoted $150 to do that.

So, $850 + $150 is an even grand. If you can find a set of LSx heads that will give comparable flow/performance for that (maybe a used set), then you might be faced with a tough decision. But almost regardless of the heads you use, you should be able to get 400 hp from a 6.0 easy...

 

I have my eye on a set of l92 heads... and as long as I can mill them down to raise compression I think I will go that route...

 

Dont bother with the crappy expensive headers, just use those manifolds. They're much better than the garbage we have to deal with for our motors.

And if you're all about LS6 heads and milling them for compression and so forth...

Have you considered getting a set of Aluminum 5.3L heads? I've heard some of the LS1 guys talking about changing over to those heads before so there is a performance benefit for it... Just a thought! And I bet they'd be MUCH cheaper than some of the other options since theyre "just truck heads". And they're aluminum!

 

If you use the L92 heads then you have to use the intake that goes with it.

I am going to run the MS4 cam kit. Like I said before as soon as I can get this thing together then I will have some numbers. I need to find another shop or someone else to do the swap.
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Also I saw that you had 1000.00 for LS6 heads. You can find them for half that price. Look on some of the other LS1 forms they are way cheaper than that.

 

Yeah I was looking at the l76 intake with it... So you mean cheaper than 1000 for the pair? which forums TGO, or LS1tech?... I'll look around today.
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I haven't looked into the 5.3 heads at all... I will definatley look into that. I also want to look into running those exhaust cutouts... one of the main reasons I want headers... But yeah 800 bux for headers makes me want to run the stock ones.

 

Does anyone know if you have to run a new torque arm, or will the stock one work?

 

Try LS1Tech. They should have some floating around or the corvette forums.

 

haha they wont fit, i think you are a bit mistaken


do it your way better off here's a link to our swap hope it helps

 

Yes, the stock LS1 F-body manifolds are quite a bit better than the ones that our cars were stuck with - but those "crappy expensive headers" have shown to be worth an additional 20-25 hp over stock manifolds...

L92s are "just truck heads" as well, and they're also aluminum. Just don't want anyone thinking that they're iron heads...

(For whatever it's worth, here are the two articles that finally convinced me to drop my plan for a Gen-I 383 in favor of a 6.0L swap... Link 1 and Link 2.)

 

Thanks for the link!

 

Socal,

I checked out the links and that is a good looking swap. I know it took some time and effort for that shop to do that exhuast. The whole swap looks real good.

I need to bring my car up there for you guys to finish it for me.

 

thanks we (my bro and i) did it all in the driveway except the exaust, now i just need another motor and tranny to do the swap on my 91z

 

How long did it take you guys to do it

 

I applied for a 5000 loan to get all the stuff to put the engine and trans in the car and running... I only got approved for 500 . I guess I will have to do this over a period of time... I am going to go with the LS6 heads and LS6 intake... I can afford those by this friday... I'll put some pics up when I get them in...

I am selling the LQ4 intake complete with rails, throttle body, and injectors... also those cast heads and the water pump with fan assembly... oh and a running 305 and 700r4... I hope that will cut the price down a little

 

I got an LS6 manifold yeasterday... and I am picking up the injectors/fuel rails/throttle body tonight... and hopefully will be buying a set of 243s from a guy on ls1 tech, Then I need to figure out a cam.... then 2 big money items trans, and headers...

 

Yeah, the headers... If there was EVER a place where the market needs to step in & introduce some competition...

I KNOW I'm very probably just going to swallow hard & buy 'em - but I'll either be cringing, crying, or cussing as I write the check...

 

I hear you all the way man!

 

Jonny if 400 rwhp is all your after you could do it with those stock iron heads. It will take a custom grind cam but its doable and cost effective. If you plan on swapping heads stock 243's are good as far as stock castings go but only if you get them DIRT cheap. One of the vendors over at LS1tech was selling BN castings last year for $230.00 for a pair as an FYI so you dont get burned buying some used ones. Also consider valve springs will need to be bought for any cam swap. Patriot Gold's are the absolute best bang for the buck and the best spring available IMO. $250.00 for a full set with ti retainers, locks, and new seals.

So keep that cost in mind when buying your heads. Also I advise to NEVER buy used valve springs this is one area where its new or nothing as far as I'm concerned.

So add those bits up and if you decide to go new you cant beat the head/cam/pushrod/head bolt package offered by patriot. You'll put an EASY 400+ rwhp on a 6.0L with their set up and then have good parts to sell should you ever upgrade.

Heres a link to the thread I posted about their package. Good luck

https://www.thirdgen.org/forums/ltx-...m-package.html

 

Be careful. If the LQ4 has iron heads, there's a good change that it's a '99-'00 LQ4. Look at the back of the motor, and if there's a spacer at the end of the crankshaft then there's a good chance it's got the longer crank and won't bolt up to a 4L60...there's a reason the older ones are cheaper. I made the same mistake myself.

 

maybe 2.5 weeks of actull work but we waited till we had everthing before we even started.

 

I will look tonight... what trans did they use in 1999 and 2000(in the trucks)... wouldn't it still be a 4l60e

 

As far as i know you can still use the 4L60e,but you need one from an earlier car ('94 - '97 F-bod)

The longer crank would be for the different pilot. Im using a '95 4L60e for my swap with a pilot spacer to make up for the shorter crank on my '03 LM7

 

cool thanks for the info... I will post my findings tonight... ok maybe thursday night hah

 

Well I looked at the back of the motor between the motor and flywheel and it looks to me like there is a spacer... I will post a pic soon(takes a while to upload from camera... in the process of. What was your solution to this mistake?

 

Here is a pic... crappy cuz it was dark




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wouldn't the only difference be with the torque converter not the trans itself