Hey, guess whos back for more questions!

Yes this swap is quite the little headache but still.

Anyways, question for today is this.

If I have a TH350 from my 79 that had 3.73 rear gears, and its being put in my 1984 with 3.42 gears, is the speedo gonna be way off?

And can I self calibrate it or must I take it to a shop?

Thanks for replies

 

You don't need to mess with the speedometer head, just change the speedometer gears in the tail of the transmission.

 

What do I look for in speedometer gears? To match my rear gears? I'm not quite sure what I'm looking for is all.

 

What size tires do you have?

 

Currently running 215/65/R15 in back. Which I'd like to add came from the 79 (since I busted my rims that one awful night)

 

An 8 tooth drive gear (6261783) and 22 tooth driven gear (2987922) should get you pretty close.

 

Ok, I'll google those numbers and try to find it. You know of any good sites that explain how the speedo thing works out because I don't quite understand it.

Btw are those GM part numbers next to the dif gears?