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318 to 440 Suspension Upgrade

RockyPat

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Hello everyone,

I am going to be swapping a 440 into my 318 71 Charger.

I know that the front suspension should be upgraded to handle the big block's weight and power.

Anyone have a guide on what needs to be upgraded or what should be done when swapping in a big block in a small block car suspension wise?

A person is selling some torsion bars for my car, but I am not sure if they are big block spec. Is there such thing as small block and big block torsion bars?

They are also used, so I am wondering if buying new is a better idea.

Thank you!
 
I don't have a Dodge shop manual, but the 1971 Plymouth FSM shows this chart which has the different diameters for various engines. Note the factory mis-spelled Satellite name. :)
upload_2021-9-16_9-49-30.png
 
Is there such thing as small block and big block torsion bars?
Yes. You will need the BB ones. Buy new depending on your budget. This upgrade topic has been covered many times with allot of good info. Do a search to find out more. In the mean time, get your wallet ready. I did a 318 to 440 swap and depending on the build of your 440 will determine how you'll need to upgrade. Also, depending on how many times you want to break down will determine how much to replace and upgrade. You will be looking at more than just suspension upgrades if you do the swap. Drive shaft, yolks, radiator, trans maybe, rear end maybe, motor mount bushings, ect. and its a fun learning project if you have the time, patients and money. Keeping it as a stock 318 will be the least amount of trips to the garage and will able you to drive it more. Starting a project (depending on your skill level) typically the car will be in the garage most of the time and not on the road.
 
Yes. You will need the BB ones. Buy new depending on your budget. This upgrade topic has been covered many times with allot of good info. Do a search to find out more. In the mean time, get your wallet ready. I did a 318 to 440 swap and depending on the build of your 440 will determine how you'll need to upgrade. Also, depending on how many times you want to break down will determine how much to replace and upgrade. You will be looking at more than just suspension upgrades if you do the swap. Drive shaft, yolks, radiator, trans maybe, rear end maybe, motor mount bushings, ect. and its a fun learning project if you have the time, patients and money. Keeping it as a stock 318 will be the least amount of trips to the garage and will able you to drive it more. Starting a project (depending on your skill level) typically the car will be in the garage most of the time and not on the road.
I applauded you Learn good ways .
 
Hello everyone,

I am going to be swapping a 440 into my 318 71 Charger.

I know that the front suspension should be upgraded to handle the big block's weight and power.

Anyone have a guide on what needs to be upgraded or what should be done when swapping in a big block in a small block car suspension wise?

A person is selling some torsion bars for my car, but I am not sure if they are big block spec. Is there such thing as small block and big block torsion bars?

They are also used, so I am wondering if buying new is a better idea.

Thank you!
 
Most are going to say you cant or should not lol its all suspension rear leaf first then torsion bars then well the list goes on.
 
I drove my 318 charger with a 440 for years with small block t bars cranked up...was the the rite thing to do? Nope....did it ever fail....nope. I have the correct ones now for 15 years or so.
 
I drove my 318 charger with a 440 for years with small block t bars cranked up...was the the rite thing to do? Nope....did it ever fail....nope. I have the correct ones now for 15 years or so.
Torsion bars are so cool
 
I drove my 318 charger with a 440 for years with small block t bars cranked up...was the the rite thing to do? Nope....did it ever fail....nope. I have the correct ones now for 15 years or so.
You know your stuff for sure.
 
I drove my 318 charger with a 440 for years with small block t bars cranked up...was the the rite thing to do? Nope....did it ever fail....nope. I have the correct ones now for 15 years or so.
5 leaf?
 
Rear are super stock...they are coming out soon and will be for sale
 
If you trunk mount the battery and go aluminum heads and intake the front end will be OK. The rear axle and leafs will need to be upgraded if you want to put any power to the ground.

I would eventually go 440 t bars and disks if you don’t already have them.
 
I don't have a Dodge shop manual, but the 1971 Plymouth FSM shows this chart which has the different diameters for various engines. Note the factory mis-spelled Satellite name. :)
View attachment 1167226

Thank you for sharing this. Very good information from a solid source! The misspelling is funny! Lol
 
Yes. You will need the BB ones. Buy new depending on your budget. This upgrade topic has been covered many times with allot of good info. Do a search to find out more. In the mean time, get your wallet ready. I did a 318 to 440 swap and depending on the build of your 440 will determine how you'll need to upgrade. Also, depending on how many times you want to break down will determine how much to replace and upgrade. You will be looking at more than just suspension upgrades if you do the swap. Drive shaft, yolks, radiator, trans maybe, rear end maybe, motor mount bushings, ect. and its a fun learning project if you have the time, patients and money. Keeping it as a stock 318 will be the least amount of trips to the garage and will able you to drive it more. Starting a project (depending on your skill level) typically the car will be in the garage most of the time and not on the road.

Thanks for the comment! Very informative, I appreciate it. Thanks for helping me with the torsion bars. I will definitely have to search the forum for more about my question. I am looking to do a mild build, so hopefully I will not have to modify too heavily. I agree that keeping the 318 would be the easiest thing to do, but it is stuck and not running. I am trying to gather parts for a BB swap slowly.
 
I drove my 318 charger with a 440 for years with small block t bars cranked up...was the the rite thing to do? Nope....did it ever fail....nope. I have the correct ones now for 15 years or so.

Thanks for comment. This is good to know, but hopefully I can upgrade them before or shortly after.
 
If you trunk mount the battery and go aluminum heads and intake the front end will be OK. The rear axle and leafs will need to be upgraded if you want to put any power to the ground.

I would eventually go 440 t bars and disks if you don’t already have them.

Thanks for the comment! I have an aluminum intake, but not heads at the moment. Front discs and upgraded rear axle are definitely on the list. I will add leafs and torsion bars to the list. Thanks for outlining good steps to take. I appreciate it.
 
Is your car equipped with an 8-3/4" rear axle?
 
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