Okay I'm looking to buy a circle d 3400-3600 258mm for my crew cab silverado and noticed freak show offers a really nice converter with the same stall speeds 3400-3600 but is a 300mm. My question is what would the difference be between the two ?

 

how much power?
towing?

the 258 is going to be the better option almost for sure

 

honestly not really sure, my truck has a 6.0 with 10.5.1 compression 223/226 .600.600 111 cam 243 heads and long tube headers with dual exhaust with 3.73 hears.

Also I very rarely tow a small aluminum boat. I will only tow with this truck if my duramax is down.

 

I had a Freak show converter was close to stock stall dont remeber exactly what stall but it was not much, worked fine till lock up cluth started slipping after 5 years with the supercharger. After the turbo lock up clutch in the converter started slipping, new Circle D 258 is a reaaly nice quality piece, I probably would not buy a Freak Show converter again after the Circle D. Not trashing Freak Show tho it did a great job for years.

 

Smaller is almost always better, for a higher stall.

It's easier to build a smaller one to act more like a "switch"; not hooked up at all below the stall speed, hooked up HARD above it. A larger one tends to not have a sharp hookup like that (typically they have to shave the stator blades to open up a gap between it and the turbine), and consequently gives away power and heats the fluid, until the RPMs are well above the stall speed.

I have no comment on the relative merits of the 2 companies.

 

Have Circle D spec you one

 

^^^^This

Converters are great and all but a custom one is going to blow the doors off any off the shelf.

Custom or personally specced out my Circle D

 

This is the norm for Circle-D

When I bought from their website I received an email asking vehicle weight, horsepower, torque, rear gear, tire size, towing, etc.