mattdel

i have reason to believe the previous owner of my car installed an underdrive crank pulley, but i have no means to verify this "accusation" of another mustang owner i work with.

can anyone tell me the stock pulley size?
any identifying marks on it? like a ford logo?

ZachW04Stang

The stock pulley is like 5in in diameter, an underdrive pulley is 3in in diameter.

raven_ghostwolf

Just went out and took a rough measurement on my 87 and it is about 5 13/16" in diameter at the ribs, under drive crank pulley should smaller.

Tims 88GT

they have ford stamped on them somewhere as well.

mattdel

under drive pulleys are actually larger, guys.

but thanks for the measurements

PRO50SC

Ummmm, no. the crank pulley will be smaller than the balancer. Trust me.

raven_ghostwolf

Accessories are larger, crank is smaller.

Tims 88GT

^^ yea yea yea as the ol wise one says

shawnk007

With underdrive pulleys, you'd have to use allen head bolts or somethin. The stock one wud have hex bolts that wont fit in the underdrive pulley.

creekrat

Wow matt. have you fallen and bumped your head? I thought a high dollar mechanic like yourself would know this! Plus all the fuel tank baffle replys?? Is this really you?