20+ years of "Building 904/727 for drag racing use"
Thank you for coming back and participating in the forum and bestowing your knowledge on us!
I've rebuilt a 727 and a 904 with good success. Both of which I put trans go shift kits in along the way... For me it's mostly changing the clutch packs and the lip seals...
I'm on here all the time encouraging people to do the rebuild their shelves..
My question would be first a recommendation for a rebuild kit? Whether it be for mild or wild and why you would think so?
I say this because there's many more people on here that are not drag racing and I feel a lot of times that there really isn't nothing more special they need than just giving it a fresh rebuild..
And also if going a little more to the wild side in both transmissions what would be your first upgrades and why?.. maybe where a guy doesn't want to go full-blown race build but just add a few things in there that will add to longevity and good performance...
Thank you very much for your time as I know it's valuable...
As for a basic paper, rubber, ring and seal kit, the majority are made by transtec and work fine. As for clutch and band materials, and clutch counts, I'm more concerned with having enough line pressure to hold a clutch or a band in a certain application. We've used alto red racing clutches for decades in all of our race builds and I don't have any complaints. Raybestos GPZs are fairly new, and we use them in all of our diesel builds with a lot of success. There would be no reason not to use the GPZs in a street or race build, either. They work very well from what I've seen thus far. Steel plates, I use standard steel plates up to 1500hp. I don't really use or recommend Kolene steels, as I've never seen an advantage for the additional cost. Bands--we use a red lining in all of the transmissions we build. Again, line pressure is more important than clutch color, as people have used Borg Warner yellows, and have done just fine.
The biggest thing I'd focus on in both transmissions is having a good valve body and setting up the transmission for no overlap. This transmission inherently gets stuck in two gears at once on the 2-3 shift, and a lot of shift kits will amplify that. A very harsh shift is not a good shift, it is a bind or overlap. You want a quick, firm shift with no overlap on the 2-3 shift. We do a lot to overcome this.
Other than that, at our elevation (6000 feet) we install a lot of low gear sets in both 904 and 727 to get a heavier, lower powered car moving quicker, and to 60 ft quicker.
