Redbull87

iTrader: (3)

Hey guys,Im fairly new to the boards but forgive me for asking as Im sure this subject has been beaten to death but using the search feature didnt really answer all my questions.

I have a blown ls1 swapped into my 87 T/A with a t56 and I just picked up a very low mileage lq4 with ls6 intake with 317 heads.Since Im only swapping motors I know all my accessories must be swapped over,oilpan/pickup,opsu,flywheel/starter can all go on the lq4 directly.The lq4 has all its sensors on it..are they the same as the ls1 or do I have to change anything out or re-wire my harness?Also my ls1 pcm will it run the lq4 with the stock tune or do i have to have it pretuned before trying to fire it up?

Anything else Im missing or is that pretty much straight forward swap with what I listed.Thanks alot for any info.

ShredSled

iTrader: (11)

few minor differences, mostly between years... what year is your LQ4? I see in your sig your LS1 is an 01...

Also iron blocks have 1 less hole on rear for bellhousing, at like 2 o'clock when looking from back, and also less holes on front for accessory brackets, so I believe you may have to drill and tap to use some of the car accessory brackets... but I could be wrong on that.

Oil pressure sending unit on back top of valley may be different too... again, depending on year...
Your harness should work fine if years are same though.

Biggest thing I can think of for the tune is the difference in injectors. It may run, but probably not optimum performance.




You may also get more response on this in the gen III engine section as this is no longer a hybrid issue once you start talking about LS to LS engine swap.

Redbull87

iTrader: (3)

I believe its an 01 lq4,my ls1 is from a 00 camaro.As for the bracket and drilling the rear bolt for the alternator...im using the oversized truck alternator so I wont be using that bracket as it is on my ls1..figured it would be the same deal on the lq4.

Injectors..would it be safer to run my ls1 fuel rail and injectors to get it running and then change them when im having it all tuned? Or run the ls6 injectors to begin with and drive it very cautiously?

ShredSled

iTrader: (11)

oh ok, all your sensors should be good to go and plug right in then.

If you're using the big truck alt/power steering bracket then you're golden, no issues, obviously, it was meant for that block.


Hard to say about the injector issue. The truck injectors are just little 19#'ers, so you'll want to swap those out anyway... but if you ran some bigger injectors (don't know what LS6 injectors are rated at?) without a tune to account for the extra fuel it may be way too rich for O2's to compensate, so you may wash the rings out, foul plugs, and get gas in the oil! Not good. Try to get a mail order base tune from the place you plan on going, if you can. I just went through a similar situation with Baker Engineering and they were very helpful on the process, they just had me mail in my ECM, they put a basic safe tune on and charged me $50 that just goes towards the dyno tune cost when I get there in person. So not sure where you plan on going for tuning, but see if they can do the same.

Redbull87

iTrader: (3)

I not using the truck brackets..just the truck alternator only which does not use a rear bracket bolt due to its larger size.Everything else is fbody parts.

I think I might just use the stock ls1 injectors first just to see if it will run..my tuner's shop is maybe a 10-15 min drive so if it sounds like its running decent enough..it will get there under its own power..slowly.

99VetteFRC

If you are running bigger injectors for the blower you shouldn't have a problem using the same injectors on the new engine, as long as there is no huge cam or such in the engine. Basically you are only going to change 20CID so that shouldn't make too much differance. Just drive it normally till you feel things out.

Redbull87

iTrader: (3)

Thanks 99vette, I was kinda figuring it should run fairly decent.Same firing order etc..just might lean out uptop is what I guess.Seems like its a straight forward swap then,is there any need to change the crank pulley or are the both the same spacing?

99VetteFRC

If you are useing f-body brackets and accesories you will need to change crank pulley from what I understand.

Redbull87

iTrader: (3)

Ok so I just went to look at the motor,it came out of an 05 sierra.hope that doesnt change anything.

99VetteFRC

In my understanding if you use truck accesories you need truck crank pulley, Vette accesories you need Vette crank pulley and so forth. I believe they are all different lenths. I think the waterpumps are diffrent lenths too, I've seen spacers online to make an LS1 pump work with truck accessories.

squirlNUTZ

My 2000 trans am has an lq9 now. I changed all the sensors to ls1. I drilled the lower hole in the block for the alternator. Some people say you don't need it. And used my factory ls1and intake and injectors as I'm still using. You will have to use your balanced from your set up now to run your accessory drive as each vehicle is specific in lenth is: f-body, truck, vette, gto. They are all different. I drove mine for 300 miles or so with the original tune from the 5.7 with no issue. I've put 10,000 miles on it since.

Redbull87

iTrader: (3)

I thought all the sensors would be the same except the opsu and injectors.Everything should just plug n play aside from that correct.Or do I really have to change every sensor out aswell?

ShredSled

iTrader: (11)

where did I miss the details on a blower going onto one of these motors??





05 will have different oil pressure sensor at back of valley, but you can just reuse your LS1 sensor.
05 is better for you anyway, it has the stronger rods, same as the LQ9.
Should be a straight forward swap.

Redbull87

iTrader: (3)

Lol yea I forgot to comment on the too,Im not running a blower...I wish but thats way out of my budget.

Is it true the lq4 has 19# injectors?Seems pretty small for a bigger displacement engine compared to the ls1.Im going to switch the injectors anyway just for startup but was curious on the facts.

99VetteFRC

OH!!! lol, Now that I reread for the tenth time I understand what you mean. The LS1 is blown-up.... not BLOWN. So sorry.

Redbull87

iTrader: (3)

lol all good.I found it funny.

ShredSled

iTrader: (11)

yeah I think all gen III “truck“ motors had the same injectors as well as intake, whether 4.8, 5.3, or 6.0.

the_merv

iTrader: (88)

LQ4 has 24.7lb/hr Injectors..if it's 01-up.

The 19lb/hr was the 1999, aswell as the 5.3.

To run that Ironblock in the F-body switch out all the front Accessories and Balancer with the F-body ones. Drill & Tap the outer drivers side boss for the Alternator Bolt..M10x1.5 thread. Then bolt it all up.

I did that with my 6.0l Block so I could run F-body Accessories.

Wam11118

HCI2000SS

iTrader: (2)

Might want to start a new thread since this one is 6 years old