400 pump mod question.

bpman1234

Well-Known Member
#1
how can you tell if the mod was done to a 400 tranny without taking the pump or valve body apart and looking at it need to use this tranny for now just want to make it was done.
 

dank GN

BlackArts Automotive (661)993-8277
#2
What mod are you speaking of? Does it have a RMVB? If you drop the pan you can see what valve body is in there and if there is a trans brake. And if the mod you are speaking of Is the one that restricts converter fluid charge you can put a gauge on it and see what the line pressure is but that really won’t tell you unfortunately. Sorry to tell you this but the pump would have to come out and then opened up to see if it has a restrictor .
 

Chuck Leeper

Waay too old!
Staff member
#4
If it's not got the mod, there are adjustable regulators out there, that go in the cooler line. It is a cartridge, w/ replaceable orifices.
Dumps fluid back into the pan.
 

bpman1234

Well-Known Member
#5
Dankgn Its not the rmvb its a 400 that was in my olds had it built for my 455 olds came out of a 72 delta 88 long shaft it was in my 81 cutlass but it got rusted out and got rid of the body .the tranny was rebuild also with some hardend parts shift kit but dont remember if he did the pump mod for the oil pressure not to wipe out thrust bearing yes tranny is out of the car just want to make sure that mod was done before i put it in the converter i have with it is tci 241000 thats was in the tranny with 455.i.also have the AC 16920 converter chuck so if i dont have the pump mod when i look do you have a part number for that adjustable regulator?gonna take the pump out to see do i have to remove the valve body or just those bolts around the pump then tap it out from the inside?
 

dank GN

BlackArts Automotive (661)993-8277
#9
You can call Chris at ck transmissions and he has a kit I believe. I have done this mod to about 5 th400s just to be safe . If u can’t find a kit I have a restrictor that I can shoot you u just would need the proper size drill and tap .
 

dank GN

BlackArts Automotive (661)993-8277
#10
The adjustable regulator won’t lower the converter charge just the cooling circuit. The converter charger comes directly from the pump .
 

bpman1234

Well-Known Member
#11
Sooooo took the pump out and no pump mod done so whats first have to get what size tap and plug ? Ido i have to plug the hole also next to the anchor bolt?same tap size? How do my surface look where those gears ride?
 

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dank GN

BlackArts Automotive (661)993-8277
#14
You should swap out springs in the pump . For better pressure . U can get all this stuff from ck performance . Just google them . He has a bunch of info on th400 on the web .
 

dank GN

BlackArts Automotive (661)993-8277
#16
all I know is with a RMTB you don’t have to run a bunch of extra stuff . I guess to make it shift by itself you need to run a cable or a vacuum line or something down to the trans . And it is different with a turbo car because of the boost . So it’s just a lot easier to do a manual VB plus it gives you something to do while driving so I don’t mind it at all actually. If I could do it over I would go with Lonnie’s 4L80 manual VB with a 4l80 trans . If u do freeway miles a OD does come in handy. With the 4L80 you get the strength of a 400 with a OD .