Technical Flex plate

I'm building a blown big block for my C cab
(Pie wagon) is this flexplate for a 454 ?
It has a large counterweight.

 

Pretty sure it is from what I recall 40 plus years ago. But, building a blown 454 is an expensive undertaking. Why look at a used flexplate?

 

One of the cheapest “new” part you’ll ever by…used ones are more prone to cracking…

 

With a blown 454, I’d look at an SFI approved flex plate.

 

YUP ^^^^^^
They start at about $65.00 and go up to about $170.00. No reason to cheap out on the part that is likely to remove part of your foot.

 

Yeah, that looks like the right one...if you're running a 6 bolt TH400 converter, like they used in trucks. It's not drilled for the smaller converter bolt pattern that we usually use, as found on the TH350 and most aftermarket converters.

 

What squirrel said.

With a blown BBC, I would opt for a new one. Why take chances
Good luck.

 

I had a squeak that some internet sleuthing suggested might be my flex plate (stock carbed 350 in my daily). I removed the flex plate and sure enough, it was cracked BUT, those cracks were EXTREMELY hard to see. Lucky me, I had a stash of used flex plates in the loft of the garage. I entered the loft, located the used flex plates and ... threw them all in the garbage (was at least 8 of them, I am NOT kidding). I then went and bought a new one, SFI rated and we all lived happily ever after

As other have said, with the cost being so low for a new one, and especially with yours being behind a healthy engine, you can't afford not to buy a new one.

Actually, now that I think about it, I believe a former neighbor took a few to use for some "steam punk" thing he was working on.

 

A average SFI flex plate in cheap Up grade ,
But it really depends on Your engine combo ,
Just because you add Blower/Supercharger does not mean you will exceed Oem strength,
If you start to exceed 500 pds of torque on automatic
More up grade I would be concerned of ,
Crack in flex usually thrust bearing problem ,
35 years ago Just to see as experiments for myself and lasted two years street & strip .
Blown with 10 psi on 9-5.1
I made little over 600 hp on stock block 400 sbc
Cast crank , stock rod , stock balancer, stock Vega converter , 400 trains up graded clutches, stock u joints , stock drive shaft ,12 bolt, 3:55 gear ,radial 3,500 pds
Et 6:50s @ 107 1/8
Took stock 454 added .530 cam hyd , 12 pds boost
1,500 pnd car 4:11 gear , pro stock tire ( size @ time 1998)
Et 5:60s1/8 again just playing around