Okay, so I have a 83 t/a with the 305 crossfire. I am upgrading to a 454 carved motor. I have read a lot of th forums on the subject but I am very confused on my wiring. I've heard people talking about pulling th whole harness out. Has anyone done this that would be willing to walk me through it a little bit? I marked as many of the wires that I could when yanking the old motor. Do I just need the distributor, power/starter/alternator? I am a first time builder and am just kinda overwhelmed. Any help is appreciated!

 

I assume you mean a 454 with a carburetor.

First, let's understand what you plan on doing with the car after this swap - daily driver? - weekend cruiser with an occasional trip to the track? - all out race car trailered to the track? The answer may affect the answer.

Are you planning on using the factory gauges, or do you plan on full aftermarket, or some mix of the two?

 

Well I was hoping to use the car as my weekend street strip car. I have kept my interior all origional and was hoping to keep my guages origional too. As far as the engine bay goes, getting rid of a/c stuff and as much wiring crap as possible. Also going to go to a electric fuel pump. It is a carb motor. Is there a wiring diagram anywhere?

 

I have found this to match my '82 well, so it should do the job for your '83.
http://www.team3rdgen.com/modules/3r.../1985_c100.gif

The ECM harness that goes to the passenger side fenderwell can be removed in one piece along with the sensors attached to it on the firewall. I believe the fuel pump relay is part of that, but I wouldn't swear to that. You can use the relay in your new set-up.

Note that the C100 contains all the lights, gauges, alternator, power, etc. that you will want to reuse. It will not be affected by removing the ECM harness. You should be able to just reattach all these wires to your big block equivalents.

 

When you are talking about the relay clump, do you mean the big bunch on the driver side firewall next to the vacuum canister and window washing box. I tried to mark as much as I could when pulling it out so as not to get too confused. I remember the harness splitting in two sections. One section goes to the throttle bodies, TP Sensor, IAC Valves and alternator. The other end went to the large relay cluster and one to the tranny, maybe one o2 sensor if I can remember right. Thanks for the diagram, that will help a lot. Will the gauges be effected by pulling the harness?. Am I right when remembering that the Distributor wires are separate from the Harness? I am looking at wiring in a electric fuel pump later (way later). One last question- The manifold that I purchased is the edelbrock performer non egr. The two small threaded ports next to the thermostat housing have me kinda baffled. Like I said- This is my first real intensive project so I am not as knowledgeable about these things as I wish to be. I am thinking that those ports are for the heater hoses?????? Can anyone clarify this for me or maybe even a picture would be great. Thanks again for the diagram!!!

 

Correct, the harness that went to the throttle bodies and transmission will not affect the gauges. The starter, power (which go to the starter along with the battery cable), distributor, tach, oil pressure, alternator, engine temp all go to that C100 connector and are not at all affected by the harness that goes to the computer.

There should be a pipe thread outlet on the front of the intake that goes to the top of the water pump with a short 90 degree hose. The others on each side of the thermostat housing are for heater hose and water temp gauge. You should be able to take the water temp sender out of the 305 driver side head and put it in one of those outlets.

 

This may sound like a stupid question but where do I go to look for that C100 connector?

 

driver side firewall to the right of the brake booster. 6mm or 1/4" bolt goes through the middle to hold it on. the headlight harness can be completely disconnected from the c100.

 

Great, Found it! Do you know if I can use my stock power steering with the swap? Any ideas for how to wire in the new fuel pump? Its kinda far away but mine as well start planning. Thanks for all the help.

 

Two possibilities for wiring the pump: 1) Use the factory wiring; 2) use a switched ignition source to turn on the factory relay using the factory wiring to power the pump from there.

You will probably be able to use the '83 power steering pump, but you will need big block brackets to mount it to the engine.