LT4 swap
 

I am getting things ready to a LT4 swap from a donor 96 Vette Grand Sport 6 speed and l need some info about it, I am waiting for the DVD and catalog from S&P which should help. Install it in my 69 10. Things that I am not sure about are:
-I will be staying with the auto trany TH350 for now will up grade to over drive later what VVS do I need to buy? 6 speed broke in the roll over crash.
-Will the trany bolt right up?
-Can I use my flex plate and starter? Or should I get one that is for the LT4 auto?
-The manual fly wheel is smaller in diameter so think the starter won't work?
-Who is good to send the ECM to, to remove VATS and what else should they do to it?
-What is a good after market fuel pump heard that there is heat problems if you don't use in tank I have everything from the Vette but don't know if I should mass with adpting it to a stock tank (just put a new tank in a while back should have went to a rear tank in hine sight). I did put a return in at the time though.
-I am thinking of modifing and using the Vette wiring I have everthing.
I am sure there is more that I have forgot about so please any input will be helpful.

Thanks Dave

Re: LT4 swap
 

Well I will try to answer some of the questions that i know from doing my LT1 swap....

I would go to Jaguars That Run for the VSS (thats what I used, it runs off the speedo cable)

My 700R4 bolted right up to the LT1 (still the GEN 1 style bellhousing)

I used a flexplate from an automatic LT1 as well as the LT1 starter

I have a universal fuel cell with an external Walboro 255 inline pump and havent had a problem, just be sure to mount it at/below the bottom of the fuel tank. (It is pretty loud w/o being intank though)

I used the complete factory harness out of the 96' Camaro donor and havent had a problem, just takes time to weed everything out and be sure you have the connections necessary to run the engine.

Check out my build thread foe more pics/info

Re: LT4 swap
 

ok a couploe of dumb ?'s what the heck is VVS and what is VATS,
I have also heard that the 77 78 79 which ever are the first gen LT1 all bolt patterns on heads trans hook up and intake are the same is this true. I am also thinking maybe someday to do a swap but only with a LS5 anything else would be pointles IMO

DAVE69 are you going to paint the GS stripes on your girl for the enthusiast to notice on the road that would be cool

Re: LT4 swap
 

The VSS stands for Vehicle Speed Sensor, and it lets the computer know the speed of the vehicle, which it uses to perform certain tasks.

I believe that the original LT1 was a standard carb engine back in the day, I doubt that anything is interchangeable, the 93+ LT1 was a ground breaking design at the time.

The LSx's are nice, but far more costly and I love the sound of the LT1 firing order more than the LSx's.

Re: LT4 swap
 

is you can check on it that would be cool because the guy that told me that about 1st gen and second bolting up he worked for GM customer servic eheadquaters anyways thought it was cool to think of a ls1 lt1 carb setup

dave are you going to use the optispark tech or go with aftermarket coil setup

Re: LT4 swap
 

LT1's have the same bellhousing bolt patterns as Gen1 BBC/SBC so no issues there. The intake pattern is different though, you would have to convert a SBC intake to the LT1 bolt pattern. The head bolt pattern is the same, but the cooling ports and oil drain backs aren't. You can use Gen1 heads on an LT1 but some coolant ports have to be welded up and oil drain back holes drilled since the LT1 is reverse flow.

Re: LT4 swap
 

VATS is anti thieft system and I am going to leave the racing strips off LOL

Re: LT4 swap
 

Ooooops, sorry I forgot to answer that part, yes VATS is the Vehicle Anit-Theft System. It wont allow the vehicle to run more than a few seconds without the proper "key" inserted into the ignition. The GM keys for these engines have a resistor built into them that has to be the proper value to "unlock" the VATS system. This is why when we swap them we have to defeat this feature to allow installation in our trucks.

Re: LT4 swap
 

Thanks for feed back does the flex plate and starter only fit from a LT1 or can I use one from an other SB?
What pulse on the VSS will I need if I stick with the turbo 350?
Will my engine mounts work and bolt up or do I need somthing differnt.

Re: LT4 swap
 

Sorry forgot to ask if you know who to send the ECM to for reprograming.
Also I have not taking all wiring and modules etc. from under the dash should I take it all out and what is needed?
Do you know how I can ID all of the senser and mudules I know a lot of them, but not all.

Re: LT4 swap
 

The pulse count varies with the different years, they state which one for which year on that Jaguars That Run site, I think mine is the 40 pulse. I used a local guy for the programming, but there are guys that do it mail order as well, I would look around the Camaro forums for this service.

I think the only important module is for the VATS (not needed if you delete it), I wish I would have taken the RAP (Retain Accessory Power) module though. It would be nice to have power for the radio/windows/door locks when you shut down and have the key off.

I used a wiring diagram I gor off of the Camaro forum for the wiring, I can PM you all the info I used if you would like.

Re: LT4 swap
 

You should only need the engine wiring harness. It will help resale of the donor car if as much of it is intacted.

PCM4less, Madwolf, etc. Google LT1 PCM tuning.

Flexplate has to be from a SBC with a one piece rear main seal or it won't boltup. You can use the LT1/LT4 plate and starter. In case you are looking at aftermarket stuff for clearance issues the flexplate is 153 tooth. A 168 won't fit under the bellhousing, at least on a T56 it won't. SBC with a one piece started in 1986.

Re: LT4 swap
 

That would be great if you can forward it, just have figure out how to use PM

Re: LT4 swap
 

Thanks I will look for that style of flex plate and starter.