86ttopbird

Well, at first I was pretty dead set on dropping a 3.4/3500 hybrid in my car, but after checking out some of these LT1 swaps on youtube, I am starting to really like that idea. My main question is how much of a PITA is it? Common sense tells me that I have to change the PCM harness, but more importantly, installing the LT1 tranny in place of the V6 one. As for fuel, I am pretty sure the V6 MPFI pump will not be good enough so I'm probably just going to get a 255LPH TPI pump. Think that will give an LT1 the pressure it needs to operate? Also, if anyone has links to where I might get fuel lines and power steering lines, id be greatful. I saw a couple in the sticky but for some reason they wont connect. Lastly what year LT1 should I be on the lookout for? I would prefer a MAF setup as I have heard that they used speed density in one or two years of production, but im not sure which ones. And from a legal standpoint,(I live in Pennsylvania) I wonder what the legal issues would be as the car is VIN'd and registered as a V6 car. Now I put a V8 in there, wonder what the inspection mechanic would say? I also have emissions here as well. But I plan on having cats and such on the car.

84redta

iTrader: (34)

Can't speak to you on the legal standpoints. The stickies on the top of the LT1/LS1 page has everything you need, LT1 power steering lines can be bent, fuel lines can be replaced with aftermarket ones, although i don't quite understand yet why lines from the car can't be mated to factory lines. You will need a new exhaust system as far as the manifolds and y pipes go, although i'm still researching why a F-Body LT1 exhaust can't be mated to existing other than size. Your v6 pump should be sufficient as it puts out the same pressure as the v8 tpi ones, body fuel lines are the same, don't bother with them, you'll probably need new v8 motor mounts, but someone more knowledgable can step in. Transmission i believe should bolt in the same as any other tranny would in a 3rd gen, meaning it should use the same mount, not sure though. I'm working myself on all the research needed myself right now to get ready to do mine.

93 is SD only, 94 is a good year because of the first year of programbable PCM, along with the SD/MAF combo being used, 95 in a camaro marks the first year that they put a vent on the OPTI-SPARK which is a vast improvement from previous years, 96+ i don't know how it would have to be worked since that was first year of OBD-II and you have additional sensors to pass inspection for 96+ laws, so unsure how to fit that into an OBD-I car.

Pocket

iTrader: (24)

Once the wiring is done, a LT1 swap is similar to any SBC swap as far as the physical fitment, mounts and exhaust

Any GEN I/II 4L60E will work well with the LT1 PCM. Be aware of the '94 difference with the extra solenoid

LT1s operate on the same pressure as TPI. MPFI V6's are essentially TPIs in many aspects, including fuel. Your stock pump will work, but depending on how old it is, it may be a good investment to change it. Since 255's are usually within a few dollars of OEM's, theres no reason not to upgrade even if you wont need all the extra flow

Fuel lines and PNs are in the Additional Swap info thread. Depending on your goals you may use only part of the diagram

PS lines must be built by a hydraulic company. NAPA usually can cover this, or any heavy equipment/repair place. Expect these to set you back $30-100

LT1s are not like 3rd gens where MAF was the old tech and SD the thing to have. Newer MAF cars are more precise and efficient than ever. Grab the newest LT1 within your budget thats not scrap. The more parts that come with it, the easier your swap will be. Break down:
92-93 SD 4L60 (Updated 700R4)
94 OBDI old style 4L60E
95 OBDI new style 4L60E
96-97 OBDII new style 4L60E

Emission swaps are a bit more difficult because donor engine must be from a newer car which sometimes must be the same model IE Camaro LT1 swap must be from a newer Camaro, not a B-body

I would consult your emissions office and insurance agency before buying anything

Carb fuel lines are worthless for a EFI swap. OEM EFI equipped cars have all the proper lines in place, they just come out at a wierd spot. You can install new lines from the old hardlines to the fuel rail and it work fine. Or for about 15' more of stainless braided, run them all the way to the tank. If you've ever replaced the fuel filter on a 3rd gen you know hardlines suck

LT1 exhaust changes are specific to the model. B-body manifolds will dump the collector into the K-member. Fbody manifolds will work fine, but so will 3rd gen manifolds. 4th gen headers dont fit the chassis. 3rd gen SBC headers fit fine as long as they have 1 5/8" or larger primaries

4L60 transmissions use the stock auto crossmemeber and mount
4L60E's require an aftermarket or modified crossmemeber

92-93 SD cars can be tuned, just like TPI chips. Remove, burn, reinstall

OBDII swaps into OBDI cars are cake. Just run the newer ALDL. Its actually harder to run OBDI swap into OBDI cars and reuse the stock ALDL

Good luck with the swap, be sure you research EVERYTHING until you can regurgitate it in your sleep. With the amount of info covered on the boards you have no reason to run into any surprises

84redta

iTrader: (34)

Here's a question, can one pick up a good deal on a '93 LT1 (complete motor and tranny), and eventually as these cars hit the yards pick up a harness from a '94+ with PCM and retune it, figuring using a manual transmission? Will the harness plug and play to the engine?

And what i meant was mating the 3rd gen's body hard lines with the LT1's body lines, so that you can use the LT1's quick connect fuel lines.

Pocket

iTrader: (24)

The main difference is the opti, and that has its own 12" harness. Swap and dont worry about it

The newer PCM cannot control the 93 auto trans, but will be ok with any manual trans you put behind it

The 93 intake and fuel rails are different than the later engines but should still work

The hard part about reusing stock LT1 lines with the quick disconnects is attaching the hard plastic fuel lines to the steel lines of the 3rd gen. If you can figure that one out, then by all means use them

86ttopbird

First I'd like to thank Pocket for his very well written input. It seems you really have this stuff down to a science. As for the MPFI V6's being baby TPI's, I had no clue lol. Wonder what they share in common? The pump is about 20 years old so yea its getting replaced because I dont want surprises. Thanks for the tip about the P.S lines, the local NAPA said no problem when i called them about it. I knew about the motor mounts and such and the hard lines being re-useable. Yes changing fuel filters on thirdgens does suck the big one. I might run braided lines if i get a good deal on all the stuff. I'm looking at the 95 LT1's. Heard alot of good things about them. That just leaves the friendly neighborhood referee station for the emissions laws and such as well as alot more research. I dont want to just dive into a project without oodles of knowlege about it.

Klortho

The intakes are different on the '93s as well with where the crossover tube is at on the fuel rail, '95 had a different opti plug on it than the '93 and '94. The Harness on the '93 is totally different than the '94 and the '94 is different than the '95 and the '96 is different than the '95 (boy that's a mouthfull).

The '95 is the best year to get the LT1, largest cam, vented opti. As for the fuel lines, you can use the old hard lines coming from the tank, they are exactly the same as the lines in a TPI car, just have to make adapters from them to the quick release that are on the LT1 fuel rail (I put my old V6 hard lines into my GTA that had no fuel lines). PS lines, since you have a V6 car, you should have the PS cooler that runs under the radiator, I took it to a local shop that made hydraulic lines and they cut the cooler line and put some ends on it so my PS lines run to the passenger side of the car, across the radiator support and then back up to the steering box, a very clean install for it.

86ttopbird

Thanks Klortho. You cleared up a few things for me. I knew i could use the hard lines without a problem. That PS cooler line trick, thats interesting. I think ill write that down along with all the other great info i have received so far.

Gordiggz

Anyone have a link to the thread for making the fuel lines mate up?

I've been searching pretty hard for it and can't seem to find it.

Also, may I suggest that Pocket be put on the payroll? I've been sorting out all my little swap details and almost every question I have is answered immediately when I see a post from him. A special thanks for the wiring harness thread!

Pocket

iTrader: (24)

https://www.thirdgen.org/forums/ltx-...formation.html

Post #9

That covers running the lines all the way to the stock sender. Plan B is to run new lines just the last 2 feet of the engine bay from the ends of the stock hardlines

5/16" return line uses a 14mm x 1.5 O-ring fitting
3/8" feed is 16mm x 1.5 O-ring as listed in the diagram

I appreciate it