hey everyone my 85z28 305tpi only has the 85mph cluster in it now and my local bone yard has an 87 roc with a 145 spedo it it. i know how to change the cluster inself but is there any special wireing required to complete the job or is it a direct swap over?

 

nope, no special wiring required

 

You might consider only swapping the speedo head rather than the whole cluster (since you are already sure your guages function) to garantee that no problems arise. While you're at it, this is the time to consider white-faced overlays and higher intensity xenon bulbs.

JamesC

 

swap the clusters first, to check how well the 145 works. they come in and out a lot easier than taking the cluster apart. I recommend droppings the steering column when you do it, cause the column gets all beat up on top if you don't.

if it works, take it back out and do some modifying if you want. white face, reverse indiglo, bright white bulbs... whatever you want. you better grab that cluster fast, too... it'll be gone before you know it.

 

I've sold a few over the years, and several apparently had electronic compatibility issues (couldn't say why), but the speedo head always functioned as designed. I believe swapping the speedo head (three screws if I remember correctly) is easier than swapping the cluster out twice. Whatever you choose to do, Cayse offers good advice about dropping the steering column. I few strips of masking tape on the column might save some scratches.

JamesC