Hello,

I am getting ready to buy a flexplate for a 1991 Trans Am. I know I need a 153 tooth flexplate, but should I purchase an externally balanced or internally balanced flexplate? Also, how is B&M for quality?

Thanks!

 

internal, and get one that's SFI approved. B&M is good, but anything with an SFI sticker is fine. should be about $40 on ebay.

 

Is the externally balanced flexplate for 400 CI or larger?

 

not necessarily. but if you're running a TPI 350 you need an internal (neutral) balance flexplate for a 1-piece rear main seal.

 

There seems to be a dispute as to what constitutes an externally balanced engine, but the flexplates on 1 piece rear main seal engines are not nuetrally balanced. B&M refers to theirs as externally balanced. At least that's how I read it.

http://store.summitracing.com/partde...5&autoview=sku

" B&M 20238.

Flexplate, 153-Tooth, External Balance, 1-Piece Rear Main Seal, SFI 29.1, Chevy, 5.0/5.7L, "

 

I looked at the pictures of the neutral balanced flex plate and it has the external weight to compensate for the 1-piece rear main seal. As it was explianed to me from Summit that is all I need to worry about. However, I am still slightly confused. So, I am going to follow the reccomendations in this post.

Thanks for the help!