Im new on here and looking for some advice, but i have a 91 RS and i'm installing an LT1 in it. I have Everything, ENTIRE wiring harness, computer, intake, and sensors. The engine is ready to go in the car and im mating it up to my WC T5.

I saw that you recently did a similar swap and i was wondering what i need to wire the system. Ive deleted the A/C and the smog pump. Everything in the engine wiring harness is hooked up except for the C100, C105, C210, C220 and C230 plugs that go to the donor car's body harness. I assume most of this should be spliced into the 91's C100/C207 body harness.

I would like to retain the factory gauges, radiator, and fan. It seems that the LT1 C100 plug has fan control wires but I think they would be useless for the 91. The rest on the LT1 C100 and C105 are power to fuse and traction control and A/C wires. Does that mean the LT1 C100 and C105 plugs are useless and can be ignored?

So that leaves just three connectors left on the LT1 harness, C210, C220, and C230. These have gauge, ignition, fuel pump relay and other crucial functions.

Any advice or direction on wiring these would be greatly appreciated. I have a friend who is a mechanic working on it while im at work, but he wants to save me money on labor and also has regular work to do so im doing the research for the wiring. This way the car will be done sooner and i can enjoy it before i deploy.

I have included some pics of my RS. I picked it up for $3k and after attempting a TPI swap onto a dying 350. I have a 70000 mile LT1 going in.

 

Start by reading this https://www.thirdgen.org/forums/ltx-...rt-finish.html

 

My swap is now complete, thanks for the tip, it was about 80% accurate and made getting started very easy. Finding a store in my town to order an OEM flywheel proved difficult but i got an RS one. Now i am trouble shooting strange noises from the drive train at low rpm and significant shake at low rpm in 3rd 4th and 5th gear. These conditions were present before the swap and are seemingly worse. The engine however runs amazing. Ill post some pictures of it soon

 

Keep us updated on how that stock t5 holds up, my brother has a 91 Z28 t5 and i'm thinking about dropping in a stock lt1 for him. I figure as long as he blows the back tires loose the t5 will be fine.

 

So far so good, and by that I mean the problems I had before the swap are still present, however there are no new problems. I believe the u joints are bad. Also the stock RS brakes are no match for the LT1 so I'll probably upgrade.

 

No problems with the T5 so far after driving the car for a month. Got the o2 sensor installed, and just recently wired the OBD 1 connector so i can finally scan it and troubleshoot. Lower control arm relocation brackets are on the way to correct the driveline geometry that was screwed by the guy who owned it before me when he lowered it. This should eliminate the terrible shake and drivability issues that come from the odd driveshaft angle and the stress put on it. (the U joints were fine). Have wander bar coming as well and EGR block off plates.

 

Slowly I have been adding or fixing the car. I have installed a wander bar, LCA relocation brackets, EGR blockoff plates, MSD wires and coil, and I cut my front eibach springs to drop the front an 1" more. The car handles great and pulls very hard; however, I still cannot get a scan tool to read the car and there is a significant shake all of the time. The engine is running strong without misfiring and when in neutral it shakes the same. I am guessing there is something up with the flywheel. I have a brand new 305/T5 flywheel and clutch, but im not sure if there is an issue because i mated it to a previously auto LT1 350? If anyone has advice on this it would be appriciated this and scanning the ECM are my last hurdles.

I have picked up a crackless dash, and will be sending the car home to have the LT1 built and the body fixed and painted. This will likely include a T56, new rearend, brakes, long tubes, and Madhammer (GMMG) mufflers on a custom dual exhaust. Im going to shoot for up to 500hp to keep it in the reasonable to drive daily category.

In the mean time i'll be picking up the rest of the suspension components and some new wheels.

Finally i believe my tach is inaccurate as the car pull strong through 6500 and long distance, I drive down the highway at 70 in 5th gear, it says ~2600. Ive been making it 330+ miles on 13.5 gallons consistantly. 24mpg in a 350ci, F YEAH! Seriously though pretty sure the tach is wrong.

 

That's great man, can you get a laptop hooked up to it with lt1 edit ect? And on the tach sitch, yeah mine is off a bit to, up until 4k it put's on 100rpms if that makes sence. Mine idles at 800rpm warm, with the stock tach.

 

To anyone following I found my issue. It was the wrong flywheel, autozone fw148 is wrong. Took it to a trans expert and the new clutch, fork and throw out we're ruined. They found an unbalanced Luke flywheel and are replacing the rest. Ill pos the part numbers when I know em. In the mean time I picked up an 89 WS6 9 bolt rear with disks and 3.27 posi for $200 with only 70k! Going in when I get the car back