When shopping for converters I noticed all these difference size for the converter housings. Most trucks ones I saw were 9.5 inch, 10 inch, 12 inch etc...
How do the different sizes affect driving issues and which ones are best? I've heard the smaller the converter the tighter it will be. Is that true?

 

A smaller converter is going to weigh less and have less rotational mass. However, it is also going to have less surface area for the clutches. In a heavy truck, you are going to need as much surface as area as possible to prevent wlipping when the converter is locked. Especially if you tow. Precision Industries uses multiple disk in their converter to increase the surface area and to shrink the converter down in size. I would recommend a 10.5" in an ECSB/CCSb configuration. I believe stock is 12.5" in the 4L80E.

 

Ok, cool so you want the smallest one possible to knock down rotational mass but you also want the most amount of surface area on the disks to provide the most amount of friction...I see the dilemma. So the bigger the converter you get the more HP loss you'll have through the drive train...I would presume.

 

The smaller it is the looser it is since there is less stator to affect Fluid movement

 

I thought smaller diameter is a looser converter.

 

smaller = looser, but its in the way its built and with what particular STR.

I'd get a 5 disk 10" PI for your truck... its a spendy piece but it will probably be the last converter you buy for that truck.

 

I have that same converter and it feels pretty loose. But then again I'm not a converter connoisseur so...

 

what kinda feeling are ya shooting for exactly??? do you have a specific desired stall speed??

 

Julien, my Yank is 258mm= 10"

Only mine is a custom 2800rpm stall

 

Actually I'm planning on putting in a yank 2600 9.5 inch and was hoping it would be tighter. But the reason I was curious about sizes is because a buddy just bought a 12 inch 2600 performa built converter and I was wondering how his would differ from mine.