Am swapping a 305 to 350 and wanted to be sure I can use my stock 305 flywheel with the manula T5.

Stock motor/trans 1991 305 / 1991 T5.
New setup: 1993 350 / 1991 T5

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After searching/reading this site I gather this:
The 305 flywheel can be used with the new 350 motor, as long as both engines have the same rear seal. Can anyone confirm?


Then, I saw that GM lists 2 part numbers for flywheels:
Vin E: 14088650
Vin F: 14088646

The 14088646 is said to be a "lightweight" flywheel ("Dewey" post). I am wondering if there is a meaningful difference between the two.

Would they use the "lightweight" flywheel on a 350 to reduce rotating mass with the idea that the 350 can make enough torque to overcome the reduced intertia of the lighter flywheel?

Main reason for this post is to double check with any veterans out there to be sure that I can use my 305 flywheel with the new 350 motor and not have balancing problems.

Any help/clarification is appreciated-

S-D

 

i can only speak positively for auto's, but EVERYTHING i've ever seen on a 305 will work on a 350

 

In short YES you can.

The difference is the 1 piece rear main seal, and BOTH your engines are 87 later so you're okay.



The lighter flywheel was used on performance applications for a lighter rotating mass. As you know, no 350 had a 5 speed behind it from the factory.

So bolt 'em on go.

As for auto's, there IS a difference when you swap from or to a 86 and earlier engine ( 305 OR 350 ) they were "zero" balanced, and the 87 later were NOT.

The flexplate ( auto ) would have weights on it 87 Later, and the flywheel ( manual tranny ) would have holes drilled 87 later, earlier units would not.


HTH

 

Onto and ctandc-
Thanks for your help- I can always learn something here.

Am getting ready to paint my engine bay- engine will go in soon and this is one more question out of the way.

Thanks again-
S-D