So I've been searching and searching and I've come up with maybe 5 results that don't really go into much detail.

If I'm tracking right, the Transgo parts should control spring pressure on the check balls while the Zip Kit actually affect flow rates.

Those things work hand in hand, I get that. What my question is: If a guy was to install both, does one cancel out the other? I don't have enough of an understanding exactly how the two affect each other. Help me out here.

Transgo good on questions like that, get up with em, don't know Zip techs.

Probably won't cancel other, might not be good together though. More flow more pressure usually equates to more heat, can cooling keep up, we know it can on one or the other haven't heard otherwise. Have Transgo kit going in sometime this year maybe.

This is an old thread, but I recently combined a TransGo kit with some Sonnax parts for the valve body on my 253k 2002 4Runner with A340F transmission and type 4 valve body (casing number 8938).

The Sonnax parts used did not seem to have an equivalent in the Transgo kit.

The Zip kit seemed to some parts contained in the TransGo kit.

Other posts go over install and are pretty good, however be sure shift trans into N and to

line up the manual shift valve with the shift lever pin during valve body install,

see attached. Shifting the transmission into N makes lining the valve and pin up easier, but still can be done in P.

When opening up the two halves of the valve body, place the upper body down, and remove the lower body off of the upper body to keep the check balls etc. in place.

Once the check balls have been adjusted per the TransGo instructions, put a dab of install lube over the remaining balls / retainers and any other items that may come loose while handling the bodies.

The high tack lube also helps holding the accumulators in place during valve body install. Keep an eye on the "3rd" acculator (C-2), it likes to fall out during install.

I combined the Sonnax boost valve and TransGo PR valve assemblies, see image attached.

The Sonnax o-ringed end plugs required a gentle tap with a brass drift to install.

Parts Used:

TransGo SK 340 Kit
Sonnax Dual-Ratio Boost Valve Kit Part No. 97741-01K
Sonnax O-Ringed End Plug Kit 97741-19K
OEM o-rings for accumulators (Edit, not used, used the ones with the kit)
OEM valve body gaskets (35433-60040 / 35434-60040)
OEM transmission oil strainer
Fel-Pro pan gasket TOS18685
Lubegard 19250 high tack install lube
Motul Dex III - 7 bottles (7.4 quarts)
Lubegard 60902 ATF Protectant - 10 oz.

OEM part numbers were from PartSouq using my VIN.

I went with the SK 340 kit because I did not want the low hold feature (if I want to hold L I drop it to L), and the valve body plate holes can be drilled to match the HD2 kit if you want the quicker shifts.

I drilled my valve body plate to 1-2 0.062" (SK 0.055 / HD2 0.076 truck ), 2-3 0.062" (SK 0.055 / HD2 truck 0.062) and 3-4 0.055" (SK and HD2 0.055.)

After driving, I think 1-2 may have been better at 0.067" or 0.076" as in the HD2 kit truck drilling.

Shifting into reverse or drive is more crisp, you can feel it.

The change in shifting / throttle response is noticeable and seems like an improvement.

I noticed that the TransGo instructions for the SK and HD2 kits show different valve body plate layouts for the type 4 valve body: the SK kit matched my type 4 valve body plate, while the HD2 kit showed the type 3 valve body plate as what I saw from what I pulled out of my type 4 valve body... Emailed them, and they said that the valve body numbers are arbitrary, I am not so sure about that. Their tech support by phone is quite good.

Good luck!

Attached Images