i have found and read the How to Remove Your Smog Pump From Your Serpentine Belt Equipped Third Gen and have found the part number listed leaves too much slack. car currently has a belt that is 99 7/8" the one on the page gave one that is 96.8" but still too long.maybe corrrect fora v8 but i found someone on another page mention needing a belt that is 91.5" in length does this size sound right and for a 90 3.1L firebird??? a lot of reading and a lot of sizes thrown around but no one confirms and leaves the question unanswered at the end. thanks!!

 

Be a lot faster to run a piece of string around the pulleys and get a exact measurement to suit your setup?
Allow for the idler position

 

dunno bout the v6 serp set up, but i ran a 98" belt on my v8 after removing the smog pump. you also have to route the belt differently, cant forget that part.

 

yeah my belt is already 99" long and the 97" still had lots of slack. i got the routing right just need a shorter belt and would like to not make multiple trips. so on that the string idea sounds like a GREAT idea and will do that tomorrow...THANKS!!!

 

Get someone to lever the idler fully in
or make allowance for it ( shorter than length you measure)

 

ok measured it best i can and i get between 91 and 92 inches in length. found someone on here mention 91.5 inches is what to get and the closest i can get at napa is one that is 91.68" if 91.5 is correct will the tiny tiny bit extra be an issue??

 

Your tensioner will take up that much slack

Hopefully you measured with the tensioner at half throw

 

my 98" belt puts the tensioner in the dead center of its range. i tried the 98.6" belt as per the tech aritcle and it had too much slack in it, and the tensioner was damn near bottomed out. so after a few diff belt sizes i found the 98" belt was perfect.

 

ok done and over with!!! in case anyone with a 1990 firebird with the 3.1l does the rerouting to get rid of smog pump the napa part number 6k905 was the tightest belt i could get on. another size down i dont think i could have gotten it on the tensioner. this part is 90.873" in case anyone wanted to know. thanks for the help everyone!!