hi everybody, i have a few questions regarding installing a transmission. right now my trans and transfer case are being rebuilt, should have them back next week. i have a B&M supercooler PN: 70268 and a temp guage in the mail to install on the truck while im waiting for the tranny. heres a bit of background info: 2000 zr2 blazer, 155,000 miles, bought it almost 4 years ago with 125,000 miles( its been down a few times for repairs). transmission was missing 1st and 4th gear for a while and i finally decided to swap out the A and B shift solenoids on the valve body. got my gears back and shifted great for 1500 miles. then one day after work it started slipping, and slipping and yeah i managed to limp it home 30 miles in rush hour traffic that day dont ask me how, by the time i made it home it seemed to be stuck in 3rd gear. anyway i parked it and let it sit for a week while i weighed my options, shop wanted almost 3 grand for a rebuild, so i was thinking about throwing in the towel, but alas i love this truck and i found a place to rebuild for about 900 pulling and installing myself. i guess my main questions are as follows and bear with me because i am not a mechanic by trade:

when reinstalling the rebuilt transmission the torque converter should be neutrally balanced right? what i mean is in my haynes manual it says when removing the trans to mark the relationship of the flex plate to the torque converter and install in the same fashion...so if everythings new it should be able to bolt up however? i guess theres only three possible orientations for the converter.

i just purchased a B&M supercooler (PN:70268) and a temp gauge to install while waiting to get my trans back...reading on pros/cons of installing this in line with the factory or bypassing the factory all together. im concerned about cleaning out the lines and cooler enough, is it as simple as using a can of kooler kleen and some compressed air to get all the particles/debris out of the system? when i dropped the pan during removal to drain what fluid i could the fluid was silver...lots of fine fine particles. dont want any getting into the rebuild.

also thinking i should get an inline magnetic filter for the return line after researching a little more...any tips on brand? good idea?

oh one more thing, when reinstalling the neutral safety switch is there risk of screwing something up drastically? my shift lever is in neutral as my manual told me to do so, but after removing the switch i think it may have clicked/ moved out of neutral..how can i go about installing that properly?

thanks.