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View Full Version : Help finishing a lt1 swap. little tech stuff please look.


7mgforce
03-07-2009, 06:13 PM
hi

so a friend of mine just recently baught a 1981 silverado. it has a fuel injected lt1 swap from a corvette and auto trans.

i have search all over the net and cant seem to find the info that i need.

TWO things.

1. When he baught it the tach. isnt working. how do we fix this and get it working?

2. the speedometer also isnt working. what cable wil we need to get the speedo working?

i have search for a lt1 swap and i came out empty handed. so please if you know a link where someone did the swap please post it here.

oh the car runs great its just doesnt have those two working.

kevindsingleton
03-13-2009, 08:21 AM
Those are pretty general questions.

The speedo cable should be a stock item, and you can probably get it from the Chevy dealer. It may not fit, so you may have to find a local speedo shop (do they still exist?), and get them to fit the cable. They can probably get you the right gear, too, since the rear end ratio and tire sizes are different from what a Corvette normally sees.

The tach is a completely different problem, and could be just about anything between the sensor and the tach, itself, or even the power connections. Without more info, it would be impossible to diagnose over the interwebs.

Chris Miller
03-13-2009, 11:16 PM
EDIT: Actually, never mind the pic. On the ignition module from the distributor, there should be a white wire and a pink wire right next to each other. The white wire goes to your tach. There might be two white wires. Follow whichever one isn't hooked up. :)
EDIT2: Also, try to make that wire as short as you can to get the best signal.
EDIT3: Forgot for a moment that the 1981 doesn't come with the 700R4 trans. Pop the speed sensor off and see if there's a gear in there. If there is, you're in business. Just get a speed sensor and cable for a 1982 C10. If not, grab an output shaft gear from a junkyard 700R4.