So I just picked my car from being tuned after a d1 procharger and cam install over the winter. The car made 540 horse and 460 ftlbs through a yank3600 unlocked. The tranny is the original stone stock unit. Obviously now the transmission is not happy with all the extra power so it's time to upgrade. Am I delusional in thinking that I could have one built that'll handle the power the car makes now from one of the site vendors? Or am I looking at 4l80e upgrade? I'd like to stay with the 4l60e if I could. Thanks for the reply's!

 

At 540hp you can get a build 60 to do just fine. There are a couple 800-1000hp Vette's running a 4L60e. A shop in Texas last week reset to 4L60e record with 8.55@164 with a 448ci nitrous Vette. Many guys running 8,9, and 10 sec. track times with a 4L60e. Rossler, Rpm, FLT, and Performabuilt all have built 4L60e that can handle 540hp, you may also have a shop local to you that can build one. I have a 4L60e in my car built by Top Gear Motorsports it's a local shop. I have 575-625hp in my car, I have many 10 sec passes on mine. Now that I've got the suspension figured out and heading in the right direction, I'll turn it up and shoot for 9's. Make sure the transmission is fully built, with all upgraded part, adding a shift improver kit is not considered "built" and will have a greater chance to fail.

 

I forget, are the stock shafts good to 600hp or do you need billet shafts at that point?

 

Let me ask this, to the guys who converted to a th400, any regrets? I'm starting to drive this car less and less on the street and when I do, it's mostly around town with almost no highway.

 

If I did mostly track racing and very little street driving I probably would switch to a th400. But I have to drive 60-70+ miles on freeways to get to car shows and car handouts, so I want the overdrive.

 

I may end up going this route, I really only leave the car on the road to "test" if need be or If I just feel like taking it out. Plus it looks like you can get a pretty robust th400 for short money.

 

I sincerely hope you are not using the stock rearend, if so that would be the weakest point I would be concerned about.

 

No. It's a strange s60

 

A built 60 should be fine at that power level.

 

I'm actually going to pick up a RPM built level 5 4l65e locally afterwork. It's brand new never ran and confirmed the serial number with RPM. They said the level 5 will be fine.

 

You will be all set with that. I run a level 7 FLT with billet input and output shafts and a t-brake. Its been 5 years now going strong behind 8-900whp.

 

wow good deal to hear