I am converting from a 300 6 to a 302. I am curious if the ignition module and wiring for the 6 cyl will work with the 302 ? I also am curious if my factory tach will still work ?

Thanks

 

yep its pretty much a straight bolt in conversion, not shure on the tach though

 

A six tach won't work with an eight.

You'll need V8 engine mount perches as well.

 

FWIW, unless it's a stroked 302 you'd probably be better off spending a little money to pep up the 300. It's a much better truck engine. If you're going to the trouble of a V8 swap at least get a 351w. My $0.02, ymmv.

 

Yes it will, if you take the cluster out and mess with a jumper. Do a search or someone will chime in as to where it is and if you have to cut the jumper or install the jumper, but it will re-program the tach for 6 or 8 cyl operation.

 

On the circuit film where it connects to the tach, there should be four posts. "B" for battery (key-switched power), "I" for coil signal, "G" for main ground, and "8", which is the post you need to have grounded as well. Having this post grounded calibrates the tach for use with a V8, if I remember right.

You could either follow the circuit trace from the "8" post to its respective contact (and wire) on the cluster harness connector, then do some research and find where it ends so you can ground it out, or you could make a short jumper wire, just long enough to connect "G" and "8".

 

If you get the engine harness for the 302, the extra ground wire is already there. If you are modifying the 6 cyl engine harness, then you will need to follow the above suggestions of either jumper between the "G" and "8" on the back of the tach, or tracing that wire to the engine harness/ignition module plug and tying it into the wire from the "G". On the 6 cyl, one plug has 3 wires in the chassis side, and only 2 wires on the engine side. That deadend wire is the "8" connection. The chassis harness has it so that it didn't matter which engine was used. The engine harness itself was made different, since the temp and oil senders are in vastly different locations.