fly1

Got ahold of a 2004r tranny from an 86 caddy fleetwood. KC valve body had a olds 307 engine. Will this be a decent core for a performance build.

olds 307 and 403

It will be fine. Once bigger boost valves, slide spring, servo and a governor change or mod will make it act totally different. Higher line pressure is key. I have mine up to 215 psi in drive. It shifts completely normal under light throttle, floor it and nice firm shifts at mid high 4000 rpms happen. Your current governor may shift as low as 3000 rpm. The cheap governor PATC shifts at 4000 rpm, I have used it. Adding the green line bias spring from the big Trans Go kit increases full throttle shifts 300+ rpms. I plan on building my spare pump with all the goodies and measure the clearance this time to push closer to 250 psi when I put the upgraded 350 in front.

fly1

Ok thanks

Firewalker

Here are some videos on the transmission, including how to modify the governor if higher full throttle shift points are desired.

https://www.youtube.com/user/spikedp...arch?query=200

Lots of info on the net and boards. TexasT

https://www.google.com/search?client...utf-8&oe=utf-8

Jakeshoe

https://www.google.com/search?client...jakeshoe+200r4

Dan out of Florida

https://www.google.com/search?client...+florida+200r4

And for some more interesting info

http://highperformanceolds.com/phpbb2/viewforum.php?f=7

We aim to please

olds 307 and 403

Dan Mascal or Dr Dan as he is known, was a GM tech for years. He has built these trans for cars in the 9's including his big torque Olds 403 in the 11's. Grinding the governor is trial and error. Get a deep pan with a drain plug for ease, since the governor requires pan removal. Also anything with power needs the 700R4 or 4L60E filter and deep aluminum pan with it over filled. I am running that setup. If your goals are lower than 12's, the sheet metal pan with a rear/bottom feed filter.