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Mopar RB engine question

4K views 24 replies 11 participants last post by  techinspector1 
#1 ·
Will parts from a '72 413 interchange with a 440? I know they are both RB's. i have all the internal components of a 68 440 but no block. I found a 413 for sale but want to make sure parts will swap. Does it create a stroker motor? what size?
 
#2 ·
xpsyclonex2002 said:
Will parts from a '72 413 interchange with a 440? I know they are both RB's. i have all the internal components of a 68 440 but no block. I found a 413 for sale but want to make sure parts will swap. Does it create a stroker motor? what size?
The 413 and 440 share stroke, the 440 bottom end in a 413 block makes a 413. But you will have balance problems, the 440 uses way beefier rods and much heavier pistons, so the 440 crank will need to be rebalanced for 413 pistons. No a 413 block with a 4.188 inch bore won't go to the 440's 4.32 inch bore.

But Chryslers are my weak point hopefully someone else will chime in.

Bogie
 
#5 ·
oldbogie said:
The 413 and 440 share stroke, the 440 bottom end in a 413 block makes a 413. But you will have balance problems, the 440 uses way beefier rods and much heavier pistons, so the 440 crank will need to be rebalanced for 413 pistons. No a 413 block with a 4.188 inch bore won't go to the 440's 4.32 inch bore.

But Chryslers are my weak point hopefully someone else will chime in.

Bogie
Correcta mundo!
 
#11 ·
413" can been peppy. i have two drivetrains from mopar 323"(318) and a 440"(452"). both similar ratio 4 speeds with 3.23 rear gears. they are rockets.

i am running a tuff 440" in my cuda, and can agree with whats been said above. they have the torque you need to really pull you forward. dont over cam and loose it all. give it at least a 3.23-3.73 gear, if you build it up.

my old 4 door valiant basically stock 323" , 4 speed hauls balls. has the 340 hp MP cam "290 hp" 268.276 .430"/.444". streetmaster single plane, summit headers, stiff springed 770 street avenger. 3.23 rear sure grip. it makes 237 rwhp, lil over 300 at the flywheel. it accelerates like the first 4 gears of a 90's 5.0L mustang 5 speed.
 
#15 ·
Yup, that is a real goal to obtain.......for a FORD 5.0
Dig that! The reality though is much different. I'm not a Ford fan, 'cept their trucks. I've been seeing some very fast Fords at the track. They are what they are.


Anyway, I'd opt for a good 400 block. Check the true tech on them and you'll know why. How about a 500" 87 octane 300C?
 
#16 ·
You cannot make a 413 block into a 440 = period.

If you find a 413, at least you will have a steel crank and decent rods. Maybe. I am not sure the 72 motor home engine has steel crank.
Most else is scrap iron..... maybe you want to salvage the closed chamber heads, unless it is a 70s motor home 413.

Later 440s pop up around here for less than $200 once in a while. The last 2 we got we gave $ 100 each for, one had a 727 on it.
 
#18 ·
Stroke said:
Don't know where you are but I have never seen one for less than 2 1/2 times that amt. unless it was a real bad smoker or knocking. What ZIP are you at?
Southern Missouri border.
No rusty bodies here either. :thumbup:

In April bought a running driving no smoker complete car for $ 250.
Pulled the 440/727 and Got 350 for the car as scrap iron. :D
 
#21 ·
ScoTFrenzel said:
You cannot make a 413 block into a 440 = period.


Later 440s pop up around here for less than $200 once in a while. The last 2 we got we gave $ 100 each for, one had a 727 on it.
Pulled the salvage yard $100 440/727 apart last night. Complete, stock intake, and bad Holley.
Found a recent rebuild = .030/.020 cast crank, .060 over with cast pistons .125 down in the hole, average BBM open chamber heads with HD bronze guides, decent valves, bearings look like new, .002 total bore excess at the top. Looks like a deglaze and rering..... defintely worth $100 for a complete engine.
Will get the usual cam upgrade, Perf RPM, carb, distributor....should make an honest 370 hp for $800 total. :thumbup:
 
#23 ·
techinspector1 said:
400 block. Bore 0.050" to 4.390"
440 crank. Offset grind rod journals to 2.200" for new stroke of 3.925"
BBC 6.135" rods. Bore pin end 0.050" to 1.040"
429 Ford flat-top pistons +0.030".
Presto, 475 CID.
Good info,
but a lot of $$$$$$$ to gain only 24 cubes over a 440/451.
BUUUUT a 400 is a short deck...... if stealth is important.
 
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