Hey im planning on putting a 355 in my 1987 IROC-z camaro. It has a five speed and i was wondering if i can use the flywheel on the new motor. THe new motor is a 1989 corvette block bored with aluminum heads. will i be able to just cut the flywheel and put it on the new motor or no. The new motor is externally balanced now but it has a flexplate on it and i have no idea what a 87 camaro motor is whether it is internally or externally. Any help would be appreciated thanks.

 

305 and 350 are balanced the same. They are both internal balance, with part of the rearmost balance weight located on the flywheel flange. In the 86-up motors, since the flange has to be circular and can no longer be balance-weight-shaped, they relocated that little bit of the weight to the flex plate or flywheel. Doesn't make any difference to "internal" or "external": both motors are still internally balanced, but with part of the weight located in a place that "looks", to the naked eye, like it's "external". Therefore, avoid those confusing terms, and stick with calling it "stock".

Your stock flywheel will work fine.

 

sorry to pull this thread from the dead, but it could help answer my question. I am going to be swaping out my LO3 for a roller 350. the above is stating 305 and 350 flywheel or "flexplate" are the same correct?

 

Yes, the 305 and 350 use the same flywheel.

 

http://www.nastyz28.com/sbcmenu.html

scroll down to flywheels section

 

To clarify slightly, a 305 and 350 of the same rear main seal type will use the same flywheel or flexplate. A 1984 350 will not use the same flywheel as a 1986 305 because the former is 2-piece rear main seal and the latter is 1-piece rear main seal.

 

saves me money for my 305 to 350 swap,,,, thanks!