Flexplate 400ci or 350ci?

[roadrunner-europe]

Good morning,

i´ve got a problem with my ´77 pick up.
First i have to say, the engine never runs well.
According to the VIN there must be a 400ci inside

CKR247F511075

Whenever something´s broken down, i ordered spare parts by this number.
Till now this runs without problems.

But now my flexplate is broken and i ordered a newone by this number however.
As i received the new, it was different. There is a balancing weight on it. After a call with the dealer, he told me that the 400ci-motor is balanced on the outside via the flexplate. So i think by myself, that this could be my problems with the engine. So i mount the new and start the engine.
Immediately the truck began to shake.
The balancer on the frontside of the engine is a 8", typically for the 400ci.
But with the flaxplate now, i don´t know further.
Is there a 350ci or a 400ci engine in?

Thanks for helping
Greetings
Chris

[b454rat]

Can't always go by the VIN number as motors could have been changed over the past 30 years. Best way to tell what the motor is is to get the casting number off the back of the block. Might be able to get tell by the numbers off the front too, they are behind the alternator.

It sounds like if you put a 400 flexplate on there and it shakes you have a 350.

[cableguy0]

DO NOT run that engine anymore with that flexplate. the 350 is internally balanced having that weight added could cause severe engine problems. 8 inch balancer is not an indication of anything they were used on almost every sbc including most 350's. you need to get the numbers off the engine itself. almost every other part will interchange between a 350 and 400. the easy way to check and tell what you have is to look at the freeze plugs on the side of the block. a 350 will have 2 and a 400 will have 3.

[jchav62]

I agree. Another way to tell is the harmanic balancer. A 400 is externally balanced and has a weight on the flexplate and also has a 'notch' in the harmonic. A 350 will have a smooth harmonic balancer with no notches. A 400 has a large harmonic balance with a notch machined out of it.

My guess is you have a 350... Running it with that flexplate with call damage to the bearings.

[Damien]

Originally Posted by cableguy0

DO NOT run that engine anymore with that flexplate. the 350 is internally balanced having that weight added could cause severe engine problems. 8 inch balancer is not an indication of anything they were used on almost every sbc including most 350's. you need to get the numbers off the engine itself. almost every other part will interchange between a 350 and 400. the easy way to check and tell what you have is to look at the freeze plugs on the side of the block. a 350 will have 2 and a 400 will have 3.

Three freeze plugs is a good indicator, although I have heard of 400s with only two freeze plugs.

[raws67]

Get the casting number from behind the drivers side head on top of the block. You might have to use a wire brush or something to clean it but it will be very clear to you when you see it. Then post it and we can identify what engine you have. Also some 400 blocks had only 2 freeze plugs like the other small blocks so thats not always a true statement. I also posted a picture of a 400 harmonic balancer because the 400 like the 454 is balanced externally on both ends. Notice the cut out on the balancer its a very noticable difference.

[Dooley]

Originally Posted by roadrunner-europe

Good morning,

i´ve got a problem with my ´77 pick up.
First i have to say, the engine never runs well.
According to the VIN there must be a 400ci inside

CKR247F511075

Whenever something´s broken down, i ordered spare parts by this number.
Till now this runs without problems.

But now my flexplate is broken and i ordered a newone by this number however.
As i received the new, it was different. There is a balancing weight on it. After a call with the dealer, he told me that the 400ci-motor is balanced on the outside via the flexplate. So i think by myself, that this could be my problems with the engine. So i mount the new and start the engine.
Immediately the truck began to shake.
The balancer on the frontside of the engine is a 8", typically for the 400ci.
But with the flaxplate now, i don´t know further.
Is there a 350ci or a 400ci engine in?

Thanks for helping
Greetings
Chris

Hello Chris.
Please read these threads to identify a 400 small block.
Counting freeze plugs is a wrong way to do it. Some 400's have 2 and some have 3. There are pics in both of these linked threads.



http://67-72chevytrucks.com/vboard/s...d.php?t=324441


http://67-72chevytrucks.com/vboard/s...80#post2789780

[OJOE]

i dont guess any of the old fokes want to say it, so i will. just take a chisel and knock the weight off.

[3r!c84]

you mean you cant run the motor with out a flywheel? isnt that what a Flexplate is?

[LONGHAIR]

Originally Posted by 3r!c84

you mean you cant run the motor with out a flywheel? isnt that what a Flexplate is?

I want to see you get it started w/o one.....LOL

You have to have one or the other, it just depends upon your transmission.

[3r!c84]

lol yeah i was thinking like how are you gona start it then lol my bad

[roadrunner-europe]

Ollah,

thank you all.

tomorrow i´ll find the time i need to work on it.

when i have the engine number, i´ll post it.

think that i disassemble the gearbox and change the flexplate.

@OJOE: i had tried it with a small angle grinder, but there´s not enough space to handle it.

tomorrow will show

THX

chris

[roadrunner-europe]

Ollah,

I did it.

Have cut out the counter weight. Now the truck run again

And to all now: Yes, it´s a 350ci.
2 freeze plugs, no cut out on the balancer and here the number

3970014

and now a new question:
at the block there is a plate attached:

REMANUFACTURED
6 8 1 9 7 9

What does this number on the plate mean?
Are there some informations to get out of it?

Don´t know, why replacing a 400ci with a 350ci

Thank you

Greeting
Chris

[cableguy0]

350's are a lot easier to come across and is a direct replacement for the 400. Its done pretty commonly just because of availability.The remanufactured 3 is probably just a serial number. There should be another number on the front passenger side of the block just in front of the had on the flat pad. That will tell the entire story of what the engine was originally out of. The only issue being that the engine was rebuilt. Whatever it was originally isnt neccessarily what it is now.

[roadrunner-europe]

Ollah,

ok, thanks at all.

next job is the lift-kit.

greetings

chris

[OJOE]

did you knock the weight off or change the flex plate?

[wfomkivdrvr]

[QUOTE=roadrunner-europe;3829067]

REMANUFACTURED
6 8 1 9 7 9

That is the date of remanufacture 6 (june) 8 (day) 1979 is the plate also with more info of bearing and bore sizing gm used a silver plate on there reconditioned motors.

[roadrunner-europe]

Originally Posted by OJOE

did you knock the weight off or change the flex plate?

Ollah,

no, i´ve dismount the 400ci-flexplate and cut it off with an angle grinder and then i built it in again. it takes me 5 hours.

@wfomkivdrvr

That´s good to know. thank you.

greetings

chris

[westofb]

Originally Posted by LONGHAIR

I want to see you get it started w/o one.....LOL

You have to have one or the other, it just depends upon your transmission.

wrap a rope around the balancer and start it like a briggs and straton...lol....eat your wheaties the morning you do this!

[wfomkivdrvr]

how far are you from waldsee or mannheim?

[roadrunner-europe]

Originally Posted by wfomkivdrvr

how far are you from waldsee or mannheim?

ollah,

about 190 mls.

herzogenrath is near aachen, at the frontier belgium and the netherlands. i´m 7 mls away from the jfc hq brunssum, if you know this.

@westofb: or take a crank, just like good old times


greetings

chris

[rigon4]

I just sold a 014 block they were made from 1974-1976 so it was rebuilt at 3-5 years old

[Colesnsty68]

so can you tell if its a 383 stroker by the notch out of the balancer?

[wfomkivdrvr]

Originally Posted by roadrunner-europe

ollah,

about 190 mls.

herzogenrath is near aachen, at the frontier belgium and the netherlands. i´m 7 mls away from the jfc hq brunssum, if you know this.

@westofb: or take a crank, just like good old times


greetings

chris

I spent a few years in mannheim and my good friend has an autohaus in waldsee and my schwiegermutter lives in bad duerkheim

[roadrunner-europe]

Originally Posted by wfomkivdrvr

I spent a few years in mannheim and my good friend has an autohaus in waldsee and my schwiegermutter lives in bad duerkheim

that´s fine, i know a girl in bad dürkheim, it´s about 3 years ago that i´ve seen her.
cause my job i´m casually in the ambience.

maybe one time i also can say "i spent a few years of my life in germany..."

greetings

chris