There are automatics that are rated to certain hp loads. The C4, although a very tough tranny, will not withstand that HP in a racing condition. You have a monster of an engine. Do some research. Here is a start.
http://www.racewithjw.com/

 

Ive got what you are looking for on ebay

http://cgi.ebay.com/ebaymotors/ws/eB...MESE%3AIT&rd=1

 

Your gettin alot of bad info, a built C4 will handle all that cleveland has and another 2-300 hp easily. Anyone that tells you a C4 wont handle 450hp doesnt know what they are talking about, frankly. Run a built C4 and dont cheeze out on the converter either. Anyways back to my original inquiry, how hard did ya have to spin that 4V as they suck for any low end torque, we turned ours to 8500-9000 to make 750hp. Especially 4V's as those heads are terrible in stock form.

 

OK, show me some evidence.

 

Wade, you are going to need something other than an off the shelf B&M converter. Something along the lines of 3000-3400stall but a tight one that doesnt slip like crazy. Continental will do a custom one, so will ATI. They will run between $600 and $1000 for the coverter, a cheap one will only heat the fluid and cost you power.

Soaring a C4 can be built to handle that much power. They are alot tougher than most people think. If I could afford it a built AOD with overdrive on a switch would be my choice.

Oh yeah Wade where's the pics man? You said you would post them.. lets see em!

 

Thanks Thumpkin. I have yet to read about that power to a C4 that was successful. If you can provide evidence, it it will be helpful. Thanks bro, awaiting for your relply.

 

Performance Auto has been doing them for decades http://www.performanceautomatic.com/transc4.htm we used them behind our clevelands for years, 750hp and 8-9k every weekend. They handle 1000, there are a zillion people using C4's with serious HP. As for the converter, it will definately have to be tight and atleast 3000, go custom. That link that was posted earlier to an ebay auction will self destruct

 

I dont have any links to the guys running them back home. A couple 9 second rides with them. Also read a while back about Level 10 building them, and some place in California.

The ones I have built with new sprags could handle 11 second times in a 68 Stang, and a buddy ran one in a Falcon with a 289 into the 10s on a transbrake. (serious 289 I know)

 

almost forgot the low 12 second Fairmont with a 351W, granted he had it under 2600lbs, but still it worked.

 

Just checked Level 10, they dont do 3 speeds anymore it seems. Might be able to call and find out more, but the site is 94 up AODE etc. Still lookin..