I have a 2002 blazer extreme 2wd. I did a 350 vortec swap on it. I kept everything looking original all except the air box and the clutch fan. Now I'm trying to go manual trans. But I'm looking to keep it looking original on the inside too. I'm having trouble finding a trans that will go in it were the shifter comes up thru the floor where the automatic shifter was in the center console. I was going to use a Camaro transmission but I didn't like how the bell housing and trans mount was offset 15 degrees.

 

You can use a 2nd gen NV3500 that came behind the 4.3 in conjunction with a console. Just use a flywheel/clutch and pilot bearing setup for the 5.7. You can use the 4.3 clutch slave cylinder, hose and throw out bearing too. Any clutch pedal setup from a 5 speed 2nd gen will work, even the one from a NV1500 that comes behind the 4 bangers. You'll want to remove the dash from the donor vehicle to get the clutch pedal out, it doesn't come out without remving the dash but will pop right in when installing. Make sure you get the nuetral safety switch and brake pedal while you're there. The brake pedal is nice to have, they're a little smaller than the automatic one and will help keep you from hitting the brake when you shift. Or, you can get a rubber that covers the brake pedal and cut down the auto one to match it. You'll be making a pretty big hole in the floor so you'll want the boot for the shifter and there's a bug hunk of sound deadening material that goes in the underside of the trans tunnel. You'll also have to put a hole in the firewall for the master cylinder location. The firewall is two pieces of metal where it goes and you'll only want to cut out the one on the firewall side.

 

All of this is good info, but I just want to add a couple of things:

• The clutch pedal and all related parts are still available new, in case you can't find, or don't want to deal with, a donor vehicle. The clutch pedal snaps into place easily without removing the dash.
• If you aren't going to remove the dash, it's way easier to trim the brake pedal in place than to remove it. I trimmed mine to match the clutch pedal using a Sawzall and put the finishing touches on it with a grinder.
• The location to cut the hole for the master cylinder is already center punched on the outside of the firewall (under the hood). You have to remove the cruise control to see it, but then it's easy to reach. Like eshaw said, you have to be careful to only cut through the outer layer of sheet metal.
• The steering column cover for a tilt wheel with floor shifter is pretty much impossible to find, in my experience.

It's really not that difficult of a swap, but you're going to spend a little time making it look stock. I covered over my LED gear display with gaffer's tape (inside the cluster) and you can't even tell it was ever there, but I still have the shifter hole in the side of my column.