A co-worker is about ready to install a 454 in his '67. Can anyone tell us if the flywheel off of a 400 sbc is properly balanced for the big block?

The 400 is a lighter counterweight than the 454, not interchangeable.

Rust,

Can you tell the difference between a 400 SB f/w and a 454 BB f/w by looking at them from say 5' away??

If so, how can you tell.

pdq67

i have a flexplate of each in the garage,, maybe i can post a pic tomorow. i haven't ever put them side by side to see the difference. could be interesting.

pdq,, the camera is only half-way good at best from about 4'-5' so it should prove well!! ha ha!!

Going with new Pioneer replacement flexplates, the weights are within maybe 1/2" in width, but the 454 is .266" thick, the 400 is .166" thick.

I know it's easy to say this now, but He should have balanced it all as a assembly. Rust, are you close to a catalog to see if they're the same part numbers? I have a Ex. balanced flywheel if you need one. I guess I could check a casting # and see if it's a 400 or 454..I'm not sure what I have..The more I think about it, we use balance plates w/ a int. balanced flywheel/flex., but we balance the assembly with it all together..Good Luck...

Definately different part numbers, FRA104 for the 400, FRA111 for the 454.

I have all three big ones, (350, 400 and 454), but my 454 is aftermarket so I can't go by it is why I ask.

pdq67

Something else to help - that imprint from the bolt flange on the end of the crank is different for each throw (stock GM) crank....SO.....you'd have a reversed image of the flange....and could go off that.

rs,

Are you saying that crank flange dowels are clocked different with respect to the "dog-knot" weights between the 400 and 454 flywheels and flexplates???

I sure hope it is this easy to tell stock one's apart from a distance....

pdq67

i think rust may have hit it with the thickness. i can eyeball that much,, if it's the same from manufacturer to manufacturer. not sure of that. the lengths could vary,, but i'd bet the thickness is almost a sure fire way. i guess they could create the same weight with longer thin plates though. at least he's working within one manufacturer. that could be the key.

rs,

Are you saying that crank flange dowels are clocked different with respect to the "dog-knot" weights between the 400 and 454 flywheels and flexplates???

I sure hope it is this easy to tell stock one's apart from a distance....

pdq67

Not really the dowel as much as just the overall physical SHAPE of the flange. The bolt holes are the same pattern, but the physical LOOK at the flange is different.

If you have a known 350 and 400 crank, just look at it from the transmission end.

EDIT - having a VERY hard time finding this on the internet...but I'm pretty sure it was in a car rag a while ago about junk yard shopping or swap meet searching....

Thanks rs,

But I'm talking about 400 SB and 454 BB flywheel ID here from a decent eye-balling distance, not crank flange ID..

pdq67

pdq,, i think rs is maybe talking about the flange o.d. pattern,, like the old 283 is a round flange. something like that. like seeing what shape the imprint shows like if it was painted or or had grease arround it,, or the like. i've got one of each of the stock ones outside. i'll see if the thickness is the same on the weights.

pdq,, i think rs is maybe talking about the flange o.d. pattern,, like the old 283 is a round flange. something like that. like seeing what shape the imprint shows like if it was painted or or had grease arround it,, or the like. i've got one of each of the stock ones outside. i'll see if the thickness is the same on the weights.

That's what I was meaning to say :D

Gotcha guys!!

pdq67

The weight is cut out by a torque conv. bolt hole on one and the other is not. I'm old and can't remember which one.

http://www.putfile.com/superfly_64_fly/images/84989

clint is right. also,, the thickness is definately thicker on the 454 as rust mentioned....... also,, it's the one with the cutout arround the torque converter bolt. 2 of the 400's i have here have 2 different looking weights. sorry guys,, not a good camera and parts not very clean,, but pics none the less. here's your 4 footer eyeballer pdq!! can barely make out the cutout arround the conver bolt hole on the flexplate mounted on the engine. that's the 454 one. hope it helps.