Ok, I haven't quite read through every post on the board (yet), but extensive searching here and on ls1tech has still left me with some questions regarding an LQ4/LQ9 engine swap into a third gen. I like the idea of a stout 6.0L iron block, not having to worry about cylinder resleeving come machining time, and the fact that they tend to be substantially cheaper than the LS1's. However I'd be grateful if anybody who's done the swap or is familiar with the 6.0L's can help out with clearing up the following issues:

Truck Intake - I've heard that it's approximately 3 inches taller than the Ls1 intake, but flows better than both the LS1 and LS6. Not particularly beautiful, but hey, function over form. It obviously won't fit under the 4th gen's oversized dash, but has anyone conclusively verified that it will/will not fit under a stock third gen hood? Anyone have numbers on the amount of clearance or lack thereof?

LS1/LS6 Intake - Supposedly the truck accessory setup gets in the way if you're putting these on, easy fix or do you have to switch completely to the f-body accessories?

Accessories - The truck accessories stick out an inch as compared to those on the f-bodies, will these + water pump have to be swapped out in place of the f-body versions? Just brackets + pump, or all accessories as well?

Power Steering Pump - Are these differen't between the trucks and f-bodies? I heard something about boiling power steering fluid over at ls1tech..

Transmission - Any difference (x-member mounting point, etc) between the 4L60E's in the 2x4 trucks vs. the f-bodies? I.e. is the truck tranny usable? What about the 4x4 tranny minus transfer case? What's the deal with the crankshaft spacers I've heard are used from the factory?

Throttle Body - Newer years are using a fly-by-wire throttle body, I assume there is no idle air control valve on these throttle bodies and that the throttle plate is now used for this function? I've heard of at least one third genner running a fly-by-wire setup, but no details on how difficult it was to adapt. If a regular throttle body is swapped in instead, how is the IAC function dealt with?

Wiring Harness / PCM - Will an f-body 99+ PCM plug directly into the truck harness? Getting a wiring harness + PCM with the engine seems the easiest and least expensive route, but HP Tuners seems to have massive support beind the 99+ LS1 f-body/vette PCM's, and I'd like to stay up on the technology curve. I suppose if I went fly-by-wire the truck PCM would most certainly have to be different..


In essence:
A lot of 98+ 4th genners are basically taking these LQ4/LQ9's and swapping all their f-body LS1 components onto the long block, can 3rd genners get away with using more of the truck components or is this essentially the route we have to take?


Thanks in advance for the help,
Bryan

 

Run the 6.0 block, '01-'02 intake (bolts right up) and hook up the F-body accessories, use a car 4L60E or a 2x4 truck tranny, plus use the F-body TB and you'll be set.

The heads on the truck engines are the same as the LS1 although they didn't start putting aluminum heads on them until '01 I believe.

 

lq9s always got aluminum heads. they are not the same as the ls1, they are actually 71cc ls6 heads. im not sure on the water pump thing though

 

Actually, the 5.3 had aluminum heads, the 6.0 didn't get them until around '01

 

Watch out. Car Tranny won't fit 2001 and before.. The rear Seal Surface on the Crank is longer on truckengines.

 

Car tranny will fit an '01. I have a buddy who has an '01 5.3 in a C10 with a f-body automatic behind it. '01 is when they changed the motor around, '00 and before are the ones to avoid.

 

truck water pump wont work with ls1/ls6 intake.
make sure its got aluminum heads(317 casting) or you are wasting time.
dont buy a 99-00 motors. long crank prevents the use of a ls1 tranny, but a reg 700r4 or a th350/th400 bolt right up. a T5 might even fit.
youd have to use a lt1 6spd, ls1 input shaft would be too long, but they would have iron heads, so im wasting time typing.
01+ motor and you are good. SOME 01-02 motors had iron heads too, so check the #'s.
lots of options out there.

 

the pre 2000.5 lq4's had irons, all lq9's had aluminums

 

i bout an 02 core motor that had iron heads.
they were weeded out that year i believe. all 03+ are guaranteed to have aluminum heads.
01-02 was mixed, from what i was told at the dealer.

 

hm, thts odd, i knw they started aluminums on all 6.0s in 2000

 

Not to get off track but you're running a carb setup on your car too aren't you? Did that make any of the swap less painless? Cause i'm starting to look at 6.0's as opposed to an LS1 for a swap and just curious how yours went. I'd probably be going with 6 speed instead of a auto though. I saw in the vids in the racing section it definitly is pulling hard. Just curious if going carb made anything easier such as wiring/fitment of accessories etc...

 

car was already set up for carb.
pump, lines, carb...etc. just made since to keep it simple.
im a bracket racer, so EFI really isnt for me.
im good with a screwdriver and a set of jets.
everyone will argue this point, but its apple and oranges.
it works for me, so i stick with it.
i dont think the 6.0 is any easier of a swap. i run a homeade heim joint type alternator bracket and a electric water pump. no accessories. truck motors sure are cheaper than the 5.7 ls1 and ls6.

 

Ya I was assuming the f-body accesories could probably be used since plenty of people swap 6.0's into their 98+ f-bodies. Also figured a custom LS1 harness would work just the same with the truck motor. I don't think going carb is a bad thing it's just not widely done so therefore you know the rule if it's not common it's not generally accepted.

 

most people bring up gas milage mainly.... but lil quirks about idling, and idle to WOT transitions....etc.
racing and going fast aint about gas milage, and your performance is in the tune, no matter what injection is on top of it.

you are correct about the accessories. car stuff works a lil better.
most brackets can be found on ebay, or pretty cheap at the dealer if you have a good source.
i think a new alternator bracket from GM was only 55 bucks, but it wouldnt work for me.
good luck.
LSx stuff sure is a lot of fun!

 

But why destroy a perfectly great working mechanism by putting a archaic carb on top of it. You can tune the injectors better, which will yield more power by being able to tweak each cylinder to perform the best, and also put 400+ hp to the wheels, run consistant low 7's in the 1/8th and get 26-28mpg on the road and still be able to drive it every day even with 4.56 gears, sounds like keeping the injection is a better route.

 

destroy?
i took a working platform and made it better.
my car WILL put down over 400 in current form.
my car RUNS low 7's IN THE HEAT.
i could drive this car everyday. it gets better gas milage than my 6.0 work truck. if it could only pull the trailer.
car gets 18mpg with a carb 5K stall and 3.70 gears. what more you want?
only way 4.56 will work, or get you any milage is with a 6 spd or OD, and both of those SUCK for bracket racing. 6spd isnt consistant, and the OD is gonna blow the fock up unless you put mega money in it. my th350.... ran a stock one for 6 years racing on weekends, god knows how many miles is on it before i got it.
just rebuilt it for only 250 bucks.
cant do that with anything else.
why would i need to tune each cyl?
my egt and wideband are right on. my track times and mph show that this automatic car can run and roll with cars with more power.
im not in this for gas mileage. sorry.

see what i mean about people picking stuff apart.
apples and oranges.

 

he's going a different route than you would be. Having the carb doesn't mean bad gas mileage automatically. 18+mpg on a 6.0 that is putting out over 400 RWHP is very good and if it was fuel injected wouldn't be getting much better. Stage20 thanks for answering my questions..The LsX stuff is definitly fun i've owned 3 fourthgens with them now it's time for something a little different.

 

if you had a 6spd car, you could prolly squeeze mid 20's out of it.
ill admit that 18mpg is easy driving. i had a fun drive to the track, made 5 passes, then beat on it on the way home and calculated 13mpg. its no set in stone #, but its way better than the 8-10 my old 383 dart headed stroker got.
my stock efi 6.0 in my 2500 only gets 13 on its best day, but it does weight 6200 pounds.