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Have questions...help/advice?

rrTor-Red

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1. Are the flex plates the same for all big blocks (383,400, 440)?

2. Is there different bolt sizes from the above engine sizes? (5/16, 7/16)

3. Is there a "heavy duty" flex plate?

Reason for the questions is this. I'm going to be putting the engine, flex plate, torque converter, tranny together and installing soon. Old engine was a 383 but going in a 400. No, I've never done this before so any advice will be much appreciated (I am mechanically inclined, some what :) )


Thanks!
 
Thanks Iraqivet01! Also for your service
 
"I've never done this before so any advice will be much appreciated"

You could match the flex plate up to the converter and mark it for future reference. If it's used stuff check all bolt holes for thread wear and elongated condition. Make sure you use the correct bolts for the crank and converter. Before bolting trans to block make sure the converter is all the way into the pump so you don't damage the lugs of the pump when you start it up.
 
Make sure you are using the right weighted converter. 383's have steel cranks and 400 are normally cast. A flex plate it just a flex plate and can be used on any B or RB block with a std car crank.
 
Don't forget to clean the flexplate bolts and use loctite to keep them from backing out.
 
Make sure you are using the right weighted converter. 383's have steel cranks and 400 are normally cast. A flex plate it just a flex plate and can be used on any B or RB block with a std car crank.

Just got my new torque converter from PTC. Great customer service by them. As far as the crank in the new engine, I'd have to check

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In regards to the flex plate and torque converter. Is there anything I need to know about the two? Or just bolt the flex plate in and make sure the torque converter is seated?

Again, can anyone verify the bolt size? I'm not near the car right now. I was going to get the ARP flex plate bolts, &/16", also put Locktite on them as well

Thanks
 
Unless you're running an aftermarket crank for performance reasons, I'd imagine you would have 6 bolt holes in the back side of your crank for the flexplate. The PTC converter should utilize the 7/16" bolt, for securing to the flexplate and I would assume your bolts to the crank are that same size. As far as "heavy-duty' flexplates...yes there are higher performance flexplates. Usually they're the SFI Rated ones and utilize thicker and/or stronger material, and may have a different shape from OEM. For my bird build, I used the B&M SFI Rated Flextplate and was happy with the fit up. No issues. I put the 440 Source SFI Rated flexplate in the Coronet, and never had no issues either. I would guess your engine is internally balanced? Either way, i'm sure PTC supplied you with the right converter for such. Make sure the flex plate has the proper internal or external balancing as well.

Good to hear PTC took good care of you. They're good folks indeed! You're getting Close!!!!!
 
Unless you're running an aftermarket crank for performance reasons, I'd imagine you would have 6 bolt holes in the back side of your crank for the flexplate. The PTC converter should utilize the 7/16" bolt, for securing to the flexplate and I would assume your bolts to the crank are that same size. As far as "heavy-duty' flexplates...yes there are higher performance flexplates. Usually they're the SFI Rated ones and utilize thicker and/or stronger material, and may have a different shape from OEM. For my bird build, I used the B&M SFI Rated Flextplate and was happy with the fit up. No issues. I put the 440 Source SFI Rated flexplate in the Coronet, and never had no issues either. I would guess your engine is internally balanced? Either way, i'm sure PTC supplied you with the right converter for such. Make sure the flex plate has the proper internal or external balancing as well.

Good to hear PTC took good care of you. They're good folks indeed! You're getting Close!!!!!

Prop:

I was very happy with PTC. I gave them all the info needed for them to make my converter. As far as the crank, all I know is that it is a "BBM 3.91" ". I'm assuming it is internally balanced.

The torque converter came with the "toothed" (starter gear wheel) wheel attached. I'm talking about that bolts to the crank side. I was gonna use mine I had from my 383. If I need to, I'll get a "heavy duty" one.

The bottom line is this. I want to put the motor, flex plate, torque converter, transmission all together with no hassles (hopefully).

Again, I've never done something like this so I'm asking question here on the forum. Whether or not dumb, I just want to make everything go together good and do it right.

Also, in regarding the flex plate. Is there a correlation how it is mounted to the crank side and the torque converter?
 
Completely understandable. You just want it to go as smooth as possible, just like anyone else. As far as mounting the plate to the engine and then plate to the converter, it's pretty dummy-proof. A 6 bolt crank has the holes offset, so the flexplate will only mount in one correct orientation. The flextplate is cup offset in the middle. Make sure when you mount the flexplate, so that offset is making the flexplate tuck in further towards the block, not cup out/offset towards the converter. Like the flexplate to the crank, the holes on your converter are also offset and will only bolt up in one correct position.

mopp_0710_04_z+plymouth_barracuda_bracket_race_car+SFI_flexplate.jpg
 
Prop:

Do you thin I should source a heavy duty plat or use my 383 one?

Again, Thanks to all!
 
Prop:

Do you thin I should source a heavy duty plat or use my 383 one?

Again, Thanks to all!

Honestly man, just my own opinion...I would upgrade to a heavier duty plate. Is it completely necessary in your application? Probably not. To me, it's not a huge expense, and it's a small price to pay for a little more piece of mind having a more robust plate down there.

Glad to help!
 
I say get a SFI plate. One of the bolts on the converter is offset, I fit the flexplate to converter before putting the flexplate on the crank & marking the the flexplate AND converter (make sure the dish of the plate is in the correct position) so the alignment is correct when doing the converter to flex plate bolt tightening, remember to Locktite those too.
 
I say get a SFI plate. One of the bolts on the converter is offset, I fit the flexplate to converter before putting the flexplate on the crank & marking the the flexplate AND converter (make sure the dish of the plate is in the correct position) so the alignment is correct when doing the converter to flex plate bolt tightening, remember to Locktite those too.

Looking for one to fit right now. Maybe I'm getting confused. I'm talking about the plate that Prop showed above.

Manual calls it a "Drive plate"
 
You are right on track. That "Drive plate" the manual is talking about, is a Flexplate.

You can source the flexplate you're looking for at a lot of places......Summit, Jegs, Mancini Racing, Mopar Performance, ect..ect...
 
Here is a flex plate I'm going to use behind my 440, which has a forged steel crank and is internally balanced. I purchased mine through 440 source. They have 2 different types available. One is SFI approved at $48.95, the other one I have is not SFI approved and cost $38.95

Here is the link.

http://store.440source.com/SFI-APPROVED-Solid-Flexplate-6-bolt-Neutral-balance/productinfo/200-1084/

They may be available through Jegs and Summit as mentioned above. Hope this helps.

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IMG_8288.jpg

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It is drilled out for various bolt patterns for the torque converter.

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http://store.440source.com/Solid-Flexplate-6-bolt-Neutral-balance-New/productinfo/200-1040/

This link is for the non SFI approved one that sells for $38.95
 

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