What stall converter for my 408 stroker

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matt030305

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Hey FABO,
I was wondering what stall converter I should get for my 408 Stroker build. This will be a mostly street driven car so I need something that can cruise and be fairly street-able.

Here’s the build:
-01 magnum block
-Hughes 360 girdle (w/ARP main studs)
-scat 4340 forged 4.00” crank
-scat 4340 I-beam rods with ARP bolts
-icon forged dish pistons (~10.5 CR with 60cc heads)
-Trickflow 190cc heads (TFS-61417802-C00)
-cometic head gaskets
-Harland sharp 1.6 ratio roller rockers made for magnum blocks (pushrod oiling)
-edelbrock RPM air gap (gasket matched)
-Holley 750cfm with electric choke and vacuum secondaries

Here’s the cam going in it:
Duration at 050 inch Lift:
236 int./242 exh.
Advertised Intake Duration:
286
Advertised Exhaust Duration:
294
Advertised Duration:
286 int./294 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.544 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.541 in.
Valve Lift with Factory Rocker Arm Ratio:
0.544 int./0.541 exh.
Lobe Separation (degrees):
110

I have 3.23s in the back but will be upgrading to a more radical gearing. I got 245/60/r14s in the back. I need it to be as streetable as possible since i want to be able to cruise on the highway without burning up my transmission. Thanks
 
If it were mine, i'd probably be somewhat liberal and lean towards a higher stall... maybe 3500+ (Im not the best on a small block), but the point i wanna make is you should run a quality auxillary cooler and a deep pan to protect your new trans. :thumbsup:
 
That’s pretty high! I was looking at converters at around the 2400-2800 mark. I have a trans cooler in it already. It needs to be able to perform in stop and go traffic
 
3000 to 3500. I run a 3500 with a 360 and 3.55 gears. Drive it all over town. Acts like a stock converter unless I nail it. Converters have come a long way in the last few years.
 
3000 to 3500. I run a 3500 with a 360 and 3.55 gears. Drive it all over town. Acts like a stock converter unless I nail it. Converters have come a long way in the last few years.
How’s highway driving with it?
 
How’s highway driving with it?
I had a similar built 408 (was a Blueprint Engines build) in my 70 Duster with a 3000 stall converter & 3.55 gears. Pulled like nobody's business and at highway speed got around 13MPG. You should be fine with 3000-3500 converter with those gears, as it will cause the engine to flash to its powerband when you stomp it. I got the converter from PTC.
 
Just fine. Been in there 4 years now. Just took it for a blast down the highway to a friends house. About a 45 min drive.
 
I'm with @Hellrats , a good convertor will have great street manners. You'll be amazed at how far they have come. I have a 9.5" PTC converter that flashes around 3500 behind a stock stroke, warmed up, 5.9 Magnum. You'd never know it in stop and go or highway driving.
 
I have a similar engine and my converter flashes to 2800 +/- and it can pull 3.23’s okay but isn’t as zippy off the li e as with more gear. I’m putting in 3.73 which I think will be perfect. I had 4.30’s at one point. A lot of fun until you have to go over 50. And that’s with a 27"tall tire.

If I was you I’d get rid of the 14’s and put at least 255/6)/15. (27 x10”)
 
I have a similar engine and my converter flashes to 2800 +/- and it can pull 3.23’s okay but isn’t as zippy off the li e as with more gear. I’m putting in 3.73 which I think will be perfect. I had 4.30’s at one point. A lot of fun until you have to go over 50. And that’s with a 27"tall tire.

If I was you I’d get rid of the 14’s and put at least 255/6)/15. (27 x10”)
I actually plan on getting another a set of Mickey street slicks in the back soon. Hard to tell how much tire I need when the engine isnt in the car lol.
 
I agree with the others who recommended a custom converter. I had Kris at Continental (now retired) build me a one for my 408. It had great street manners. In fact, you couldn't even tell it had a higher stall until you mashed the peddle and then it flashed to 3500 and you were off like a bullet.
 
I’ll call dynamic up. credible companies I’m assuming?

the three companies above are the ones that always get recommended in converter threads. i have personal experience with dynamic and have had awesome results. have friends that have had great results with ultimate.

call any of those three. be 100% honest with yourself and them when giving them the information on your combo and just as important intended use. the converter can and will make or break the combo. if not 100% honest about the combo and intended use you run a good chance of not being happy with it.

the current converter i have behind a pretty stock 360 is a 9.5" unit from dynamic and will flash to around 3500 rpm but drive around on the street like a stock convertor. hell we did a 5000 mile road trip in the car last october and it performed great. i don't even run an aux cooler.. only running the stock cooler that goes through the readiator.

modern good converters are very effecient. gone are the days that 3000 converter was considered the limit for a street car.

a good converter isn't going to be cheap but they work and work very well.. you have already spent hard earned money on a stroker build, don't short change it with a cheap converter. the proper converter will really wake a car up. i see way too many guys over the years spend all kinds of money on the engine and trans only to put a crap converter in the car and leave a ton on the table.
 
I'd go with a 4200-4600.
I also had a converter around 4K in the car and it was a pita. 430 gears that converter and a motor that makes peak power around 5600 rpm was only good for one thing. 1/8 mile from a dig. Otherwise it was completely annoying.

I have a 402 and the OP is talking about a 408 and these things are torque monsters. It starts at Over 400 ft pounds around 2000 and the curve is nice and flat all the way across the top. Power started to fall off on mine around 5600. The cam in. Mine is slightly smaller than the OP.

I would never run a 4200-4600 converter in this combo
 
I also had a converter around 4K in the car and it was a pita. 430 gears that converter and a motor that makes peak power around 5600 rpm was only good for one thing. 1/8 mile from a dig. Otherwise it was completely annoying.

I have a 402 and the OP is talking about a 408 and these things are torque monsters. It starts at Over 400 ft pounds around 2000 and the curve is nice and flat all the way across the top. Power started to fall off on mine around 5600. The cam in. Mine is slightly smaller than the OP.

I would never run a 4200-4600 converter in this combo
Well, converter technology has come LIGHT YEARS ahead of what it once was even 10 years ago. You can have a converter made that will flash to 5,000 RPM but drive around on the street like a stock converter. They don't have the slipping transmission feel anymore. His camshaft will be coming on like Katie bar the door at about 4K. He'll figure it out, I'm sure. I admit you're right though. The strokers do have an incredibly FLAT torque curve, so it would probably work well most anywhere in the curve. If it was mine, I would want the converter to be all over peak torque.
 
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the three companies above are the ones that always get recommended in converter threads. i have personal experience with dynamic and have had awesome results. have friends that have had great results with ultimate.

call any of those three. be 100% honest with yourself and them when giving them the information on your combo and just as important intended use. the converter can and will make or break the combo. if not 100% honest about the combo and intended use you run a good chance of not being happy with it.

the current converter i have behind a pretty stock 360 is a 9.5" unit from dynamic and will flash to around 3500 rpm but drive around on the street like a stock convertor. hell we did a 5000 mile road trip in the car last october and it performed great. i don't even run an aux cooler.. only running the stock cooler that goes through the readiator.

modern good converters are very effecient. gone are the days that 3000 converter was considered the limit for a street car.

a good converter isn't going to be cheap but they work and work very well.. you have already spent hard earned money on a stroker build, don't short change it with a cheap converter. the proper converter will really wake a car up. i see way too many guys over the years spend all kinds of money on the engine and trans only to put a crap converter in the car and leave a ton on the table.
That’s good to know. I definitely didn’t want to cheap out on a torque converter and since I have the engine out, it’ll take less than 10 minutes to swap out the converter.
 

Well, converter technology has come LIGHT YEARS ahead of what it once was even 10 years ago. You can have a converter made that will flash to 5,000 RPM but drive around on the street like a stock converter. They don't have the slipping transmission feel anymore. His camshaft will be coming on like Katie bar the door at about 4K. He'll figure it out, I'm sure. I admit you're right though. The strokers do have an incredibly FLAT torque curve, so it would probably work well most anywhere in the curve. If it was mine, I would want the converter to be all over peak torque.
You’re also right about converter technology. I think a lot of dudes like to buy off the shelf for instant gratification and cost. Me too mostly on the cost end of things. If I was ever happy with anyone of my cars and didn’t want to change things up as often as I do I would also likely buck up for a ‘made for me’ converter to suit the exact setup too.

The converter I have now is a billet job (the 2800 one I mentioned earlier) was made to go behind a massive torque 505 big block that I had on hand so I used it. I didn’t know what it was good for and just tried it, luckily it was close enough to my needs but truth be known for my current setup I’d probably like something around 3200rpm, maybe 3300
 
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