cap42

Putting up a post as I am going to need some help from you LS experts, I've been slowly rebuilding my 71 Nova over the last few years. I am still in the rust replacement hell. Hopefully be done with that in the next few months and then can move to bodywork. Since I had the drivetrain pulled to replace and smooth the firewall I decided this was the time to swap in a LS style drivetrain.

Disclaimer, I used to wrench professional 20 years ago, I have been a hobbyist since, I know absolutely nothing about these newer GM engines/transmissions (aside from research on the internet) so I will need help and recommendations. I will also ask a stupid question here or there so bear with me.

I picked up this 2000 LQ4 with 170k miles on it. The truck was driveable and the only issue was the trans wouldn't go into reverse, the seller sent me a video of the truck running/moving and even doing a burnout. The seller had a 99 4L80e that was fully functioning and included in the sale. The motor came complete with all accessories, wiring and ECU. The seller delivered it to my door which was very helpful since I don't have a engine hoist or stand at the moment so right now they are just laying on my wheel dollies.


This picture is when I was labeling the wiring and taking it off the car. There are still a number of connectors I am trying to figure out what they are so I can complete the labeling. I may ask a few questions if I can't figure them out later.



So some of my first questions:

1. It has a 170k miles but it ran, When I pull the pan I'll know more about it's condition. Do I pull the heads as well?
2. Since it's a 2000, it has iron heads, should I just keep those and take the weight penalty or would you recommend swapping on another set of heads?
3. Anything other than the bearings, possibly piston's and cylinder walls to look for (if it's recommended to pull the heads)?

My short term goal is to get the car back to a running/driving state. Once the car is completed I may look at adding a turbo to it. For now though I don't want to have a engine build holding up the progress if I can help it. I simply want a 400rwhp or higher streetable cruiser that is reliable and fun to drive. So at minimum it will be getting a cam/spring upgrade, depending on funds and how the rest of the investigation goes it may get some other upgrades.

Suncc49

72 Nova here... I used a 500.00 junkyard 5.3 w good oil pressure. I pulled the valve covers and it looked virgin... I had to use the Holley pan so I pulled the pan and peeped the cylinder bores and could still see cross hatching on them from the factory... engine looked great inside for 100k+ miles... You shouldn't have to pull the heads.

400whp out of 6.0... - decent camshaft will get you there .. springs and do the trunnion upgrade while you are in there. I used the Straub trunnion kit.

cap42

I believe I've seen your thread over on SNS, I need to do a better job of keeping that thread updated.

I plan on upgrading the springs, trunions and the oil pump. The oil pan may be a cut down stock trunk pan or I may grab the Holley 302-2. I have a local guy that has welded a few of the cut down trunk pans that has offered to do mine, I may take him up on and spend the money elsewhere.

jeffs55chevy

i agree, i would just pull the pan, and valve covers and go from there.

cap42

Updating this thread a bit, looking for some advice on a few items.

Pulled the pan and the valve covers while I had it on a stand. A bit nasty but aside from long overdue oil changes I didn't notice anything wrong. It's hard to see in these pics but I didn't see anything scoring on the cylinders walls and I still saw crosshatches in the bores.








This one exhaust valve has some oil in it, all the rest looked good.


There were several exhaust manifold bolts snapped, I was able to use heat and a good set of pliers to remove most of them. There are still 2 that are below the surface of the head that I can't get to. If I keep these heads I'll have to try drilling/welding/easy outs to get those out.

So based on these pics, would you send this off to a machine shop to have it hot tanked, and refreshed? Or just clean it up outside and run it and change the oil frequently and hope it doesn't burn oil?

Also with these iron heads I'm seriously thinking of swapping to an aluminum set and then doing the valve job and trunion upgrade on the aluminum heads. If I go that route do I stay with the 317's or do I look for a set of used heads? If I go to another casting which ones should I grab the 243's or?

BillyFargon

My engine looks the same as yours. I am going to run it. My thought process is get it in, get it running and driving. No need to open up a can of worms unless you see actual damage. Start enjoying the car and then think about upgrading after driving it a while. I want to get mine in and then find a good replacement that I can rebuild on the side at a slower pace.

Suncc49

the truck was running and driving and could do burnouts.... use it! that is on the dirtier side, but it ran right?

You are doing the cam right? You will find out more when you pull that... also inspect your pushrods for any odd wear on the tips etc.... could need to refresh lifters

cap42

Yes Cam and lifters will be done.

Any recommendations for the heads? I am really wanting to take more weight off the nose of this thing, do I just grab the aluminum 317's or grab another casting for additional power? I mean if I'm swapping the heads might as well grab ones that will work better right? Not looking to purchase new afs heads or anything.

cap42

Just so you guys see where I am at in the overall progress of the car. I threw the motor and trans in for mock up last weekend, with the firewall modifications and making sure the trans tunnel didn't need to be modified. Still have to throw the fenders and hood on to make sure it all clears. I don't foresee any problems but figure do it now and not regret it later. It will all come back out again in the next few weeks so I can weld up the firewall, swap the oil pan etc.

You Nova guys may notice I relocated the wiper motor to the driver cowl, used nutserts for mounting and created my own extension arm. It's not shown in the pic but it's all done I just need to weld one end of the extension on.





I am using the dirty dingo LS adapter plates, I'm told I am 11/16 back from stock motor location currently and I still have another 2ish inches of room. I may go back even further once I get the trans cross member bolted in. Right now it's just being supported by a jack.

hookemdevils22

iTrader: (12)

Iron LQ4 heads are just portly 317's. If you're really just wanting to get it up and running, just run the engine as-is and upgrade down the road. I would, however, do a leak down test and consider replacing valve stem seals.

-TheBandit-

iTrader: (1)

I would do new valve seals or at least one new seal for that leaky valve, otherwise run it all day long and twice on Sundays. If you're still seeing crosshatch in the bores they are probably in good shape. You can do a leakdown check if you aren't sure or attach the starter and a compression test, but those are really just general indicators on a cold motor.

For engine mounting location, keep an eye on exhaust and oil pan clearances. Those are your two primary concerns. Make sure you can turn your steering wheel lock to lock without tie rod interference and mock up your headers to make sure they clear the steering box. Double check the tailshaft to make sure you are roughly centered at the transmision mount. Then Once you find a suitable position, match mark the slider plates or even tack weld them to keep them from shifting down the road.

petro55

I had to slide the motor all the way back to get my headers to fit(kooks full length) Otherwise they were hitting the steering box. Might want to get some headers for mock up to verify placement of the motor and trans. Might as well measure the engine angle while you are there.

ryeguy2006a

iTrader: (27)

I would take the suggestions from above. I see too many people take perfectly running engine's and take them apart opening an expensive can of worms. Even with a cam swap you can run into the infamous project creep phrase, "while I'm in there I might as well ____". Then they are into their motors for another $1k and a bunch of time.

Remember most of the fasteners on LS motors are TTY which means they can't (or shouldn't) be reused. So when you pull the heads you are looking at a minimum of $100 bucks for new gaskets and new TTY bolts, or most people upgrade to ARP so they are re-usable which adds more $$.

If it were me in your shoes, I would focus on what it takes to get the motor/trans into the car. Also would be a good idea to keep in mind future upgrades and what accessories you plan to run. If you want a low mount AC compressor for example a notch to the frame is required. The mounts/headers/pans for these cars and the 1st gen fbody's add up quickly.

cap42

Thanks for the suggestion of checking the engine angle, I am waiting a trans mount so I can check the trans cross member. With so much room behind the motor I am going to go one more bolt hole (at least ) forward on the dirty dingo mounts.

Before the motor comes back out to weld up the firewall I wanted to check the hood clearance and I am glad I did.




One of the boss holes for the beauty cover and the PCV connector on the intake were hitting the inner hood structure.




Cut down the boss as I won't be using the beauty cover and removed the PCV connector.
​​​​​​


Now it fits properly, this was a all day affair as I was doing panel fitment and messing with shims to get everything lined up right. The hood shown here is a stock hood off a 70 I bought a few months back and it's the first time it's ever been on this car. My original hood was rotted under the front trim.




I need to know what to do with the PCV connector on the intake, is there a replacement option that will point the vacuum line and sensor connector 90 degree's or can this be put somewhere else in the intake? I've tried searching for this and only seen people modify the frame stands to lower the motor or go with a cowl hood or cut the inner structure. All of these options are not what I would consider optimal but if it's what I have to do I will.

cap42

Did a search and didn't find any concrete information so hopefully someone here can chime in.

I've been looking to swap the heads and intake, the heads simply because the iron 317's are heavy and don't really add to the performance. The intake is because I need some hood clearance and I don't want a cowl hood (I know there are multiple ways to fix this). But someone local to me is selling a brand new never run LS3 top end (heads, intake, TB, injectors, rails and hardware) for a really good price. I know this is swapping from a cathedral to rectangular setup and what all that does performance wise. What I'm looking for is what other modifications or changes need to be done? Looking for total cost or total headache this would be if I pulled the trigger on this deal?

G Atsma

Total cost is up to you. BTW, iron 317's are actually 373's
Anyway, you will lose a cc in the chamber, so a slight compression increase
Otherwise, bolt it all down. Done.

cap42

The heads are stamped 317's but are definitely iron, should they have a 373 stamping?

I'm sure others can relate, they think they are getting a good deal for something only to find out that it's going to cost more for all the little things that weren't considered (nickel and dime affect). I'm all for putting rec port heads/intake on the car as it should get me to my power goal without needing a power adder (looking for 400-450rwhp)

I just don't know enough about LS engines to know what I am really getting into and everything involved. It doesn't help that there is a ton of information out there with nothing exactly clear cut like yes this works but you need to do x,y,z etc.

G Atsma

GM cast all their numbers in the head. If stamped, someone else did that. Usually the number is cast below the valve cover rail on the corner of the head.
If you have everything, it should all bolt together and look like an LS3 when done. Use a new set of early style head bolts.
You might want to switch out the early LQ4 cam, which is the same as the 5.3 cam (191/190, .457/.466, 114 LSA) for something a little healthier.

cap42

The number is cast into the head not stamped

Thanks for the info, makes me less worried about buying this setup.

I'll definitely be switching out the cam to something aftermarket, I'll have to talk to some vendors and see what they recommend. I'll also swap lifters while I am at it.

cap42

Been some time since I posted, didn't have the funds at the time to grab that ls3 top end from last year.

Looking for advice on which cam I should throw in. I've tried to do the research and understand everything but keep coming up short on what would be a good cam spec. I was all sold on the 54-459-11 but after looking at the spring recommended I was $900 into just cam/springs. I just dropped a bit of coin on other things so trying to be budget minded on the cam.

Goals - 400-450rwhp through the 4l80e, this will be a street driven car. Yes I'd like a little lope at idle, nothing crazy just enough to make it sound like a classic car with something under the hood, but don't want to sacrifice low speed driveability as that will be 95% of what this car does.

Going to swap in 243/799 heads, the current heads need to be reworked and if I picked up a set of used heads I'd have to do that to those. Might as well get a better performing head and drop the weight while I am at it.

I have a new melling high pressure oil pump, new holley 302 pan, billet barbel, new timing chain, ls7 lifters and new trays, new rear cover with seals, ARP crank bolt. Still need to pick up a trunion kit and new head bolts, so the cam/springs and I'll be all set with the major stuff.