340 to 372 stroker kit

-
logan_searching

logan_searching

Active Member
Joined
Sep 18, 2013
Messages
34
Reaction score
41
Location
Denham Springs, Louisiana
For starters I have little knowledge in building motors so I’m trying to learn as much as I can. Car is a 1972 demon (also in the member restoration section) that will be used for occasional good weather trips to work and local cruise ins. I want to be somewhere around 450-500 hp. Would like to run on premium pump gas with/without octane booster.

Currently have a 340 block bored .060 over
55cc W2 heads

Looking for opinions on the 372 stroker kits.
Which companies offer the best deals for quality balanced forged rotating assembly?


My father has recommended Scat but also wanted to see others opinions and experiences.
 
I like Summit Racing but there's others. Get the forged and balanced rotating assembly. 65'
 
For a 372 you will need a 360 crank with the mains turned down to 318-340 size, you could use factory rods resized. I'm thinking pistons might be custom, I wouldn't think you could buy .100 over 360 pistons, however I dont know this for sure.

If you were going to buy a kit from Scat or another company of that nature, just go with a 4" crank for a street machine. This is a tried and true combination already. No point in spending money for a smaller cubic inch combination unless you are racing and class rules dictate.

With your block at .060 over, I would be sure to have it sonic checked for thickness to make sure it is suitable for a performance build. I would suggest doing this before ordering any rotating assembly.

I have a W2 head 408 in my Dart and it pulls like a freight train, you would have similar results with a 4" crank in a 340 block with your w2 heads.
 
cpearce said:
For a 372 you will need a 360 crank with the mains turned down to 318-340 size, you could use factory rods resized. I'm thinking pistons might be custom, I wouldn't think you could buy .100 over 360 pistons, however I dont know this for sure.

If you were going to buy a kit from Scat or another company of that nature, just go with a 4" crank for a street machine. This is a tried and true combination already. No point in spending money for a smaller cubic inch combination unless you are racing and class rules dictate.

With your block at .060 over, I would be sure to have it sonic checked for thickness to make sure it is suitable for a performance build. I would suggest doing this before ordering any rotating assembly.

I have a W2 head 408 in my Dart and it pulls like a freight train, you would have similar results with a 4" crank in a 340 block with your w2 heads.
Click to expand...

We were thinking that by going with the 372 kit the block would require less clearance work therefore saving money while still gaining some cubic inches
 
logan_searching said:
We were thinking that by going with the 372 kit the block would require less clearance work therefore saving money while still gaining some cubic inches
Click to expand...
There is usually no clearance work required on most sb mopar strokers. My K1 crank, and Scat I beam rods went in with no grinding necessary.
 
cpearce said:
There is usually no clearance work required on most sb mopar strokers. My K1 crank, and Scat I beam rods went in with no grinding necessary.
Click to expand...

Thanks for your knowledge on this
As I have very little I only know what my father and the guy building the motor were thinking.
Any more advice or input are welcome
 
As said...If you use the Scat 4340 I beam rods there is not clearance problem with the 4 inch stroke....
If you go with the 3.58 stroke in the 340 block ...just use 360 pistons with the correct bore size...ICON makes them...and I believe SRP makes a .070 over piston for a 3.58 stroke....I know Icon does cause I have a set in an engine.
 
check out the thread down the list on 3.79 strokers- maybe some ideas there
IMHO both the 360 crank and 3.79 have been replaced on street builds by the more popular 4" strokers
you can cut down the compression and cam and still have more torque with 30 more cu inches
your top end hp would be about the same with either stroke as it is mostly head determined
short stroke takes more rpm than long stroke
your build is like A Js with a slightly smaller bore
pencil out several combinations
coordinate compression/ cam gears/ converter/ usage car weight and how you want to drive it
also what 70 cuda said \
think of the 360 crank build as a big bore 360 you will spend less than on a stroked 340 :)
from what i see an aftermarket new crank is not much more than the work on a 360 to make it fit
also do not forget to include balancing
 
Wyrmrider said:
check out the thread down the list on 3.79 strokers- maybe some ideas there
IMHO both the 360 crank and 3.79 have been replaced on street builds by the more popular 4" strokers
you can cut down the compression and cam and still have more torque with 30 more cu inches
your top end hp would be about the same with either stroke as it is mostly head determined
short stroke takes more rpm than long stroke
your build is like A Js with a slightly smaller bore
pencil out several combinations
coordinate compression/ cam gears/ converter/ usage car weight and how you want to drive it
also what 70 cuda said \
think of the 360 crank build as a big bore 360 you will spend less than on a stroked 340 :)
from what i see an aftermarket new crank is not much more than the work on a 360 to make it fit
also do not forget to include balancing
Click to expand...

Will look into this thread thank you for your help
 
Yes Icon does have the makings for a 372, Maybe try IC741+70 or IC 742+70, This picture is an alternative to piston material choice AND is for use with a 4.00 crank.
dsc04566-2-jpg.jpg
 
Although a little pricier than the scat, Molnar technologies is worth a look at on the stroker stuff, too. If putting a set W2 heads on a 4 inch stroke .060 over 340 at 423 cid, a set of aftermarket ductile iron caps with studs with a girdle would not be a bad idea. That would really depend on the severity of usage and how much strip time the car may see.
 
id be more middle of the road with it and look at some 3.79 stroke cranks! give ya more ci than a 3.58 stroke cause thay say even W2's ant enuff head for 4.0 stroke! gotta figure the money along with expectations and intended use, pick your poison,pay the piper!
 
Last edited:
I was going to mention the 3.79 as well, it’d make a 401 inch engine in the op’s bloc. At the risk of bench racing, it would have a little more piston stability and less rod angularity than the 4 or 4-1/8 inch stroke engine. It would work very well with a set of mildly prepped W2 heads.
 
logan_searching said:
For starters I have little knowledge in building motors so I’m trying to learn as much as I can.
Car is a 1972 demon;
I want to be somewhere around 450-500 hp. Would like to run on premium pump gas with/without octane booster.
Currently have a 340 block bored .060 over
55cc W2 heads
My father has recommended Scat but also wanted to see others opinions and experiences.
Click to expand...

I’m in the process of this right now. I’m purchasing parts cheaply as the deals come in. There all new, just sold inexpensively for one reason or another. I’m down to a sonic checking blocks for slugs.

No matter what parts you get, kit or singular, they should all be forged. On the rods, the base Scat/Eagle Upgraded rods can hold 500+hp. You’ll be in good shape. A great kit is a Scat set up.

As far as larger stroke crank kits, there is good thought behind the idea of bigger is better. You’ll make more torque, but you really can’t get a head to “Properly” feed it. A ported W2 comes close for race applications. On the street, it’ll be fine. Considering your stated use of the car, ether stroker IMO is a win.

On my future engine and the car it will be in, a huge amount of torque is actually less desirable for a light A body & its target.
(Same as yours. A well done 318 will spin the tires without mercy for hundreds of feet.)
The induction will be a 6 pack and ported Edelbrock heads a/a roller cam.

Being you have W2 heads, keep the compression under 10-1 for pump gas. This is your problem with 55cc heads. You may be in for custom pistons. Also because of the bore size. It is not common to find a slug over 4.100.

A well ported set with 2.08’s will move the air. A cam duration @.050 in the mid 250’s will make the power.
 
Garrett Ellison said:
I was going to mention the 3.79 as well, it’d make a 401 inch engine in the op’s bloc. At the risk of bench racing, it would have a little more piston stability and less rod angularity than the 4 or 4-1/8 inch stroke engine. It would work very well with a set of mildly prepped W2 heads.
Click to expand...
True, but it’s small in differences. I’d rather opt for the 3.79 stroke myself. But it gets a little pricey on the off beat stuff. So the 4.00 arm would be choice.
 
Wow, that's a lot of money. Why not just get a 360 and use it. Bore it 30 over, put on your heads and call it a day.
 
Hellrats said:
Wow, that's a lot of money. Why not just get a 360 and use it. Bore it 30 over, put on your heads and call it a day.
Click to expand...
That was actually my next suggestion, this with w2 heads will easily achieve the 460 hp goal. There are many FABO members with very hot running 360's. You would be money way ahaead doing this. If the 340 block sonic checks well, use it. One has to be realistic about the outcome vs. Financial outlay.

The first thing I would do is read the book I suggested a few posts back.
 
This happens in nearly every post...
The op wants info on the 372 stroker.
Replies try to talk him in to building something else!
I too would like to hear from memembers that have info on a 340 stroked to 372.Personaly i think this would be the perfect engine for a light A body!
 
Yep and it's still a lot of money to get to the same thing as a overbore 360. But if you got the money carry on.
 
ir3333 said:
This happens in nearly every post...
The op wants info on the 372 stroker.
Replies try to talk him in to building something else!
I too would like to hear from memembers that have info on a 340 stroked to 372.Personaly i think this would be the perfect engine for a light A body!
Click to expand...
It is also someone who admits to having little experience with these engines. I feel part of the value on FABO is getting information from experienced people, who may be able to help you keep some money in your wallets while achieving a similar result. I also feel the 372 is a great combination in the right application.

Perhaps you might not view these suggestions as trying to talk him into something else, but rather offering another more experienced perspective or option they may or may not have considered due to their limited experience.
 
You must log in or register to reply here.
-

Back
Top