700r4 shift kit question

[entodad]

This forum seems to be the best source for tranny info  
I just finished rebuilding my first 4L60E and incorporated an orange box transgo shift improver kit along the way as per Crosley's advice.
Now I am doing another 700r4 for my extended cab PU, a couple of questions come to mind.

1. what shift improver kit do you recommend?

2. On the inside of the Reverse imput housing there is what appears to be a defect in the metal, this is a swirl that extends from the bottom to about half way up the side.  I plan to replace the housing, but is this how a crack usually appears in this piece? or is this a rare defect?

Thanks in advance
Doug

[Crosley.In.AZ]

there is a reason the tranny info is good here.  Many members here have worked on a few of them.

I have 3 decades experience with them. I owned my first tranny shop in 1981.  I still build them for a living (?) 5 days a week.  I built 2 performance type  4L60E trannys today.

Year of your truck / tranny?

Since you you said extra cab truck I will go with 1988 - 92 truck?

Get the TransGo JR kit for the tranny. That is all it needs.

If it is an earlier version of the 700 I have different suggestions

The only shift kits I will recommend are TransGo.  Sonnax builds some neat parts for various trannys too.

I do not understand the description of the drum crack / problem

Down size the hole in the aluminum piston for the reverse input drum.  Plug the large OE hole and drill a .060 on the opposite side.

This forum seems to be the best source for tranny info  
I just finished rebuilding my first 4L60E and incorporated an orange box transgo shift improver kit along the way as per Crosley's advice.
Now I am doing another 700r4 for my extended cab PU, a couple of questions come to mind.

1. what shift improver kit do you recommend?

2. On the inside of the Reverse imput housing there is what appears to be a defect in the metal, this is a swirl that extends from the bottom to about half way up the side.  I plan to replace the housing, but is this how a crack usually appears in this piece? or is this a rare defect?

Thanks in advance
Doug

[entodad]

Once again great information!
Yes the truck is a 1989.
As to the drum, I would post a pic, but I have no digital camera  
The defect is on the inside of the drum where the clutch tangs engage the drum.  It starts about 1/2 way down on one side and spirals downward to the bottom of the drum, it is not present on the outside of the drum, but since it is of a two piece design this is not likely to have occurred. This is something I have not seen before and as such I will not put it back into the tranny.
The tranny slipped badly in OD when I removed it from the truck (I was towing a heavy trailer with another current project on it (a '66 Chevy truck), I limped home the final 70 miles in 3rd gear), However when I disassembled the 3/4 clutch pack it was not burnt. In fact none of the clutch packs appear burnt, but the fluid is a nice dark brown/black color.
As per my first two tranny rebuilds I plan to replace all bushings, thrust bearings, both sprags, and anything else that looks goofy.
Crosley, thanks again for the advice.
Doug