What rpm is peak torque made on stock 1970 440 Engine? Need info for converter.

[1Bad70Charger]

I have a 440 engine in my 69 Roadrunner built to stock specs. for a 1970 440 engine, and I am running a slightly hotter cam than stock (284/484 I believe), Hedmand Headers, Edelbrock 800 cfm carb, and 440 performer intake, 3.91 gears.

I am trying to choose the proper stall for the street on my car that will be driven 99.9% percent of the time on (the street).

Question:  At what rpm does a stock 1970 440 engine make its peak torque at and with my simple changes made to an otherwise stock 1970 440 engine, with 3.91 gears, do you think the peak torque would change with my engine and if yes where do you believe my peak torque is being made?

Thanks in advance! 

[68X426]

What's it going to be used for the other 00.1% of the time? 

Chrysler says that the 1970 440 produced 480 lb/ft torque at 3200 rpm.

http://www.440magnum-network.com/info/tech/engines/bigblock/440magnum.shtml

Check with the cam designer for the figures on their particular cam.  If not available on-line then call the tech departments, they are almost always a great help.

[1Bad70Charger]

Its late and I am extremely tired and not thinking real clear, riddle me this, the rule of thumb is to pick out a torque converter that stalls 500 rpm under the rpms that your peak torque is made (or do i have that backwords)?   

[Cooter]

If it is indeed a "Purple Shaft" .484/284, that is more than "Slightly hotter than stock" cam..It comes in at 241 @.050 Duration....I've heard Those are ground on old Crane "Fireball" cam cores...Hence, the long duration/short lift...I reccomend a 10" 3500 Stall Converter, but you might even get by with a 2500-3000, but it will not perform as well as the first..

[1Bad70Charger]

If it is indeed a "Purple Shaft" .484/284, that is more than "Slightly hotter than stock" cam..It comes in at 241 @.050 Duration....I've heard Those are ground on old Crane "Fireball" cam cores...Hence, the long duration/short lift...I reccomend a 10" 3500 Stall Converter, but you might even get by with a 2500-3000, but it will not perform as well as the first..

Thanks for your insight Cooter. Within a year or so I will be building the top end of my 440 with Eddy Heads (84cc) and this cam that Ron (Firefighter) suggested for me. I want to do the converter just once and what converter do you recommend for me knowing eventually i needs to perform great on the street  (without being a drag car) with this interesting cam suggested by Ron:


CompCam XE285HL with specs of:

Intake 545 Exhaust 545
Duration@.050 Intake 241 exhaust 247
Lobe Separtion 110.0 Installed @ 106.0 Intake Center Line

[firefighter3931]

Jim, go with the dynamic 9.5 vert 

It won't stall as high with your mild combo but will work fantastic with the upgraded combo. 

Ideally you want stall to occur at peak torque or slightly above. 



Ron

[1Bad70Charger]

Jim, go with the dynamic 9.5 vert  

It won't stall as high with your mild combo but will work fantastic with the upgraded combo.  

Ideally you want stall to occur at peak torque or slightly above.  



Ron

DONE and done, converter search is over, took advantage of the last day of the sale of the Dynamic Street/Strip 9.5 converter that  Dynamic also recommended for my application.  It will be custom built for my car and where I am headed with it in the future (built up 440 making over 500+ horse, and I was told it should flash around 3500   and feel great driving around town.  Pumped up about this converter and the Transgo TF2 shift kit, it should feel like an extra 75 shot of N20 coming out of the hole!    Of course I am going to go with a great external tranny cooler and probably run a larger tranny pan to run more tranny fluid and keep my temps as low as possible when tooling around town, hitting cruise nights, and having some fun on the weekends at my local test and tune industrial strip location.  

Ron, thanks for steering me to Dynamic they really seem to know there stuff and build a great product and thanks to EVERYONE else who has chimed in about what converter I should go with!  

[SeattleCharger]