73 Dodge Charger 400 big block help!!!

[Michaelgt450]

Hello my name is Michael this is my first time post if I post it in the wrong spot sorry you could move it. Anyways I'm building a 73 Dodge Charger 400 big block automatic transmission 727 automatic. It has 87,000 miles one owner my dad recently we got some bad news about him he was diagnosed with cancer.. and I'm building this car for him I really want him to just drive it but I don't really know anything about Chargers or Mopar for that matter so I might need some help what are the torque specs? What it has now is 11 to 1 compression aftermarket  Pistons ..a cam the specs are 480 lift I forgot the duration and some headers and I'm planning on getting RPM Performance Edelbrock intake and a 650 Edelbrock carburetor any help would be appreciated

[70 sublime]

My father also bought a 73 Charger with the 400 motor in it
Still around too but very rusted away

Was your motor rebuilt at some time ?

[Michaelgt450]

That's cool man.. he rebuilt it back in 80 something the things I'm reusing are the Pistons stock rods and crank and block my dad also put 383 cylinder heads

[ACUDANUT]

That's a cool thing to do for your Dad. I however doubt it has 11 to 1 compression.
A Holley 750 is a better choice for the carb.

[Michaelgt450]

Thanks you're probably right... we did check piston to valve clearance it has a lot of clearance... maybe I can sell the 650 and get a 750 Holley carburetor what are the Bolt Bolt torque specs..

[Michaelgt450]

What exhaust should I get he doesn't want it loud I was thinking Dynomax super turbo muffler 2 and 1/2 in?

[John_Kunkel]

You can download a copy of the Factory Serviced Manual here:

http://www.mymopar.com/index.php?pid=109

A must have for torque specs, etc.

[Michaelgt450]

You can download a copy of the Factory Serviced Manual here:

http://www.mymopar.com/index.php?pid=109

A must have for torque specs, etc.

Thank you for this are the 1970s the same torque as the 1973?

[ODZKing]

Thank you for this are the 1970s the same torque as the 1973?

Doubt it. I have a copy of the service manual as well as parts book on my site as well.
http://www.retrorarities.com/images/73DodgeServiceManual.zip

[Michaelgt450]

Thank you for this are the 1970s the same torque as the 1973?

Doubt it. I have a copy of the service manual as well as parts book on my site as well.
http://www.retrorarities.com/images/73DodgeServiceManual.zip

Thank you so much this is exactly what I needed I have one more question are these cars is the engine internal balance or external for stock .... what's a good harmonic balancer replacement... the stock harmonic balancer the rubber is coming off and it needs to be replaced

[Nacho-RT74]

Welcome and great you will help on your Dad's Charger.

Torque specs use to came associated with bolt size and metal grade ( and the metal piece is tightening up ). On this case head bolts are 5/8" as far I recall torque must be around 55 lbs on an initial step then raised up to 70 lbs. ( this is not way diff from other manufacturers ) to be torqued on this order:



383 heads won't be diff from the original 400 heads, unless they are pre 68 heads which are closed chambers. I seriouslly doubt you got 11:1 CR with stock pistons at least, not even with closed chambers. Unless got custom pistons or stroked engine ( and with some decking job added ). HiPo pistons variety for 400 are limited to ONE as far I know... Hypereutectic KB 240.

Stock pistons are rated into the 8.2:1 CR, and that's just being a blueprinted engine. Usually Block deck height and combustion chambers are way bigger than specs and you could get a 7.5:1 CR on a 400

400 uses to be external balanced since they are cast cranks. Some earlier 4 speeds 400 got forged crank which are internally balanced but those are not really common.

[Michaelgt450]

Welcome and great you will help on your Dad's Charger.

Torque specs use to came associated with bolt size and metal grade. On this case head bolts are 5/8" as far I recall torque must be around 55 lbs on an initial step then raised up to 70 lbs. on this order:



400 uses to be external balanced since they are cast cranks. Some earlier 4 speeds 400 got forged crank which are internally balanced.

Thank you for your warm welcome and it is a process to put these engines together I'm going to need all the help I can get.
It's a 400 727 automatic 3 speed so I'm guessing external balance what's a good replacement for the harmonic balancer I think the crank is cast... at least it felt like that it doesn't have stock Pistons it has aftermarket Pistons but 11 to 1 compression... with this be a good replacement harmonic balancer. https://www.summitracing.com/parts/ati-918601e/year/1973/make/dodge/model/charger

[John_Kunkel]

Those dampers are nice but a lot of money. Is your damper missing or just used up? It can be rebuilt for a fraction of the new ones.

https://damperdoctor.com/

[Michaelgt450]

Those dampers are nice but a lot of money. Is your damper missing or just used up? It can be rebuilt for a fraction of the new ones.

https://damperdoctor.com/

They are a lot of money it's just used up where can I get it rebuilt?

[John_Kunkel]

Click on the link to damper doctor.

[Nacho-RT74]

dunno what is happening with the images I'm posting ( hosted from anywhere on the web )... and I can't find it now

it came from here but I was pretty sure I posted the jpg link!!!

https://lh3.googleusercontent.com/proxy/D8GpB6iL60YrKJ0snUiYpAtknmeBLeDMkD0dix4Tsd_IjTUV3jI48mudZ_ZjBP_EB77uNvs9DNm5wYXqZijEFQXQ

[Michaelgt450]

Click on the link to damper doctor.

Thank you so much I learned something today that the engine is external balanced I may get that balancer or just rebuilt it what dampener do you have do you have a aftermarket.... I checked my crank crankshaft it's cast

[Nacho-RT74]

at least it felt like that it doesn't have stock Pistons it has aftermarket Pistons but 11 to 1 compression...

wondering where they came out from ? never have known about "out of the shelf" HiPo pistons for 400s aside the ones I mentioned. Maybe back in the days?

[Michaelgt450]

Thank you all for the help  it slowly coming together  I already got the harmonic balancer from that place  you recommended
What kind of spark plugs should I run should I run copper?
Also which aluminum water pump housing will work for my car? Part number? Also what alternator to run I have the stock when but I want to get a little bit better one any ideas of what is a plug-in play upgrade? Also the starter I have the stock one but I want to get a lighter one and a high-torque one any recommendations plug-in play I've been looking at a Mopar license starter are those any good? Also anything I can do to make it a little bit faster make more horsepower while I have the engine out I did add a windage tray the mr. Gasket one

[Nacho-RT74]

wow!!! what pistons are those ?

[Michaelgt450]

Iris something like that 11 to 1 compression Pistons my dad back in the day pay $400 for those

[Nacho-RT74]

but, brand?... PN? $400 ? that's the same price of the KB240 hipereutectic flat top pistons!!!!!

[Michaelgt450]

but, brand?... PN? $400 ? that's the same price of the KB240 hipereutectic flat top pistons!!!!!

It's been so long my dad doesn't remember the PIN he said the brand was Iris or something like that's the same price for Flat Top piston these are not flat top are flat top stock?

[Nacho-RT74]

stocks are flat top... KB240 are flat tops too but higher CH than stock and with valve reliefs

[Michaelgt450]

stocks are flat top... KB240 are flat tops too but higher CH than stock and with valve reliefs

Nice to know thank you.... I have the OEM water pump housing but it's heavier and I want to upgrade to a aluminum one do you know of any? That will work for my engine?