BBC Flexplates

[DieselBurb]

Will a 454 flexplate work on a '71 402? /forums/images/graemlins/dunno.gif

 

[4X4HIGH]

NO, 454 is all by itself when it comes to flexplate/ flywheel. 454's are externally balanced and the rest of the BBC's are internally balanced.

 

[thor]

No the 454 is externally balanced the 402 is internally balanced. A 350 on will work on the 402 though as both are internal.

 

[DieselBurb]

How do I tell the difference between an internally and an externally balanced flexplate? Will the internal be missing the extra weights on it?

 

[DieselBurb]

Bueller???? Anyone????

 

[Leadfoot]

I'll tell you in the next day or two when my SFI flywheel comes in the mail (thanks to JEGS).

As of right now I have a 454 externally balanced. It had an externally balanced harmonic balancer, an internally balanced flywheel (for manual 4 speed tranny), and a counter balance weight (to make up for the zero balance flywheel). I am installing an automic so I needed a flexplate. I decided to go with a zero balance flexplate and use the counter balance weight as I will turn this into an internally balanced 489-496 someday down the road and didn't want to have to buy two different flywheels, plus I know the counterbalance won't change this way.

When it comes, I will snap a pic or two for you.

 

[DieselBurb]

Sweeeet, thanks!!

 

[Leadfoot]

I forgot to snap pics, but it looks exactly like one used on a SBC 350. No additional weights or material removed.

 

[DieselBurb]

Thanks for the info. /forums/images/graemlins/thumb.gif /forums/images/graemlins/waytogo.gif