While we have a car torn apart, I noticed several wires in the harness that are brittle and cracked, so now is the time to replace it. What is the best harness to get? I am also deleting our A/C, so do I need to get an A/C harness or a non A/C harness from the firewall forward? We also have the HEI ignition. Our existing wiring harness was wired for that. I'm not sure what I need to buy. Anybody know this?
M & H is the Caddy www.wiringharness.com I would give a number 2 to www.Lectriclimited.com The problem is that what you are doing dictates a custom harness. There are differences between the year models so it is not as simple as buying another year model harness for your car. Be prepared as the dash harnesss is the most complex and therefore the most expensive. The engine and the dash harness will total $500 or more.
Thanks Jim and Matt. I just went to MH site and see that I can request the HEI piece. I only need the engine harness for now. The dash harness seems fine and everything works. Thanks again.
Since you are doing a custom set up you can use my engine harness . New engine from a 71 . No noticeable difference where your concerned. Just make the same cut into the harness you did on yours and add the HEI wire. If I do not sell it soon it will find its way onto my 72 GS 350. As for the underdash harness you still have the inside box and controls so ytou need an A/C harness unless you have a custom one made. I might just have a very nice underdash harness for you .
If you go with a new harness, make SURE you double check that all the wires at the connectors are in the correct places. Bought one from M&H several years ago and everything was great except they had switched the two wires at the alternator connector. Took me a while to find it too. Kept running the battery down and I couldn't find out why.uzzled:
I ordered the M&H engine harness. I don't need the under dash stuff thank goodness. Thanks John. keep that one for the 72.
perfect timing for this thread, I also needed a complete harness also for my 71 X clone, and so I ordered a complete harness today from M&H. thanks, :gp:
I happen to be at that stage too. My application is a 67 skylark. I just need the engine harness. Not sure what to get though. I'm swapping a 300 to a 455.
Hey Sillyoldman. Call M&H and they will go through it all with you and custom build the harness for what you need and it won't have all the wires you don't need. I haven't received mine from them yet, but they were very helpful on the phone. Good luck.
I called MH. That was a waste. I talked to a tech guy. He said they offer a e harness for either a sb300, or a bb400. He said the 400 harness might work with some mods. I asked what would need to be done to make it work. He said "I have no idea". Does anyone know if the 400 harness will work? Just got off the phone with LL. Tech guy was a jerk, and wanted to challenge me more than help me. They do not make custom harnesses either. I suppose if I knew the difference between temp sensor...ect locations of the 400 and 455 I'd been more help to them. The fact is that I don't know squat about wiring. I had an expectation that they should be able to tell me? Am I the first person to put a 455 in a 67 skylark? I'm surprised nobody has thought of it before me. (venting)
I would think the 400 harness would work as engine same dimensions as 455. main connection is at starter. I would think that was the same and as long as connections are same as alt and coil shoud be OK.
