Where is the best place to look for a 3:9:1 differential to lower the gearing on my 86 XT GL (EA82 NA)? Also, what about pistons and/or cams to up my compression ratio?

remember that you will have to swap the entire transmission with the rear end to match gears. but also, a non turbo trans should already be a 3.9 gear. you can only have a different rear gear if you run your 4wd as a RWD, removing a front axle.

 

a non turbo mpfi should have 9.5 compression, the highest with stock pistons, you already have as high as they come stock, or swapping in other stocl parts.

I would tend to guess that the XT has a 3.7 in it, especially if its an automatic.

 

I think the 3.7 is more suited to street use personally but to each his own.

So much for that idea.... back to searching the board for more mods.

so what exactly do you have in mind for mods?

I just picked up a 2" catco cat, and once I pick up a new Y pipe, I will have my local shop finish my exhaust system (I already have a 2" muffler). After that, I was looking at a higher compression - maybe 10:1? I'm not big on turbocharging cars that weren't designed for it. I had also looked at flywheels and pully kits.

 

I don't neccessarily want a dragstrip car - I'd rather have more GT performance.

You realize, of course, that many of these cars came with turbo. True, the compression ratios are different, but this could be a complete bolt-on affair.

Wouldn't the turbo choke on my 2" exhaust?