Hopefully sometime in the not too distant future I'll be swapping my 305 TPI in my 91 for a 350 TPI. I've been checking up on everything I'll need for the swap, but I'm unsure about if the flywheel will work. Can anyone help? (it's an automatic)

 

The only issue is year, not engine size. If its a one piece rear main 350 you swap in, the flexplate is fine from the 305.

 

Thanks Madmax, I'm just trying to be extra sure on everything while I'm waiting on the funds. I guess I need to get in the 21st century and stop referring to a flexplate as a flywheel...

 

People do that all the time. I do it myself. Only time I ask which is if I dont know if the car is stick or auto.

 

Uhhhh.....so a flywheel is not necessarily a flexplate, one is for an auto and one is for a manual? I thought maybe it was a preference what you wanted to call it - hmmm...

 

a flywheel is for a manual transmission, a flexplate is for an automatic, there are to totally different looking thigs.

even if you swap the motor and it doesent work, a new one is only like 50 dollars tops, unless you go with an ultralight ultra strong racing type.

 

Got it now, thanks everyone. Happy Holidays

 

what about manual fkywheels?? will they swap onto a 350 from a 305??

 

Yea, manual trans, auto trans, doesnt matter. The flywheel/flexplate will swap. If you have the engine in your car already, the only problem would be going from one type of crank to another, meaning from a one piece rear main seal to a 2 piece rear main seal, or vice versa. If you are swapping from another car though, some are larger in diameter and wont fit inside the 700r4's or T-5's bellhousing and you would have to get a new one. People that run into that are ones swapping in a 400 or big block or to a small block from a v6 or 4 banger. If you already have the 305 or 350 in the car, you can use whatever flywheel/flexplate is in the car aside of the rear main issues. The changeover year on the rear main was 86 for most of the SBC's. I havent verified that across the GM line all 86's were one piece rear mains, I suspect there may be some 2 piece rear mains in some trucks.

Technically, the auto trans has a flexplate and the manual has a flywheel. I sometimes refer to the auto trans flexplate as a flywheel, and lots of people tend to do that. Its not really correct to say that though. Calling a flywheel a flexplate though will probably get you some funny looks.