Hi, im going to swap out my 700r4 for a 5 speed, in my 86' IROCZ and i have two flywheels and im wondering if anyone knows the part number that will fit it? one flywheel is GM4.. 866861 N..F14, and the other one says GM1... 14085727 N... 153x. thanks, basically im just asking if either of these flywheels will work in my 86 305.
thanks
Nick:hail:

 

What you need is a 153 tooth one piece rear main flywheel. One from a 350 will work just fine as well. So count the teeth on one of them. It has to be 153. Then see if it bolts up to your crank. If it does... you're good to go!

 

alright thanks, but i also was wondering, what is the difference between the one piece rear main, and the two piece rear main flywheels? aight thanks!

 

anyone? i really need help:hail:

 

Just to make it easy on you, 168 tooth flywheels are 14" in diameter, 153's are 12-3/4"

The difference between the 1pc and 2pc rear main flywheels is the bolt circle, 1 pc wheels have a smaller bolt circle and the two are not interchangable.

 

a two piece seal flywheel has a bolt circle of 3.5x", a one piece seal flywheel has a bolt circle of 3", not interchangeable.