Originally Posted by hcompton
Dont buy a used trans. Get a rebuilt one like one this guy sells.
Level 1 Rebuilt 700R4 4L60 Transmission 2WD or 4x4 | eBay
Its a good deal for a great trans he will also work with you to get it installed right with the correct linkage and lockup options.
He can do the close ratio upgrade but its not needed. The low first gear is great pulls you out the whole and second is your power gear. Usally works great with torque build. It is also only a little off not a major change like granny gear truck trans.
Also will let you run 1500 rpm on the highway. Really helps on fuel and noise on the road. Also makes your engine last a little longer if you need to drive it on the highway for any length of time.
I honestly was thinking more in the vein of him building his own.There are a number of guys that have gone the route of Trans-Go shift kit,Vett servo,5 boost valve.The thing is it doesn't address the sun gear.The failure there is either the splines gets stripped or the weld breaks.
Yrs ago TCI impressed me.They are a very progressive class company.First check we received as contingency money was from them.All the rebuild parts address the issues that 700R4's have.From their monster sun gear to a number of stages in their valve bodies.They developed a valve body that eliminates the critical TV cable adjustment.So either for a you build or to buy of their trannies,it is a nationally known company with a excellent customer service department.
But we need to let the O/P post to see what direction he wants to go.