Is it possible to fit the valve body from a 47re into a 48re?

 

Yes, but depending on the year, you will need to swap some stuff to make it work.

2000 and newer just change the rooster comb.
99 and older will require the electrical and harness be changed as well.
Do not swap park rods. Leave your 48re park rod in your 48re.

 

Dang - wasn't there something else that changed between the small-case and big-case trannies?

 

Power Stroking,I think that I didn`t get the memo.Could you fill me in on why anybody would want to put a 47valve body in a 48 tranny.I thought these where a much better tranny.I need to work on my 47 re some time.The 70hp egde seems to over power it a little.

 

I wouldn't want to put a 47 in a 48 at all. The 48 is a much more advanced valve body and capable of making much more line pressure.

 

How? From what I've learned the line pressure is dependant on what your pump supplies, the PR vlave and spring, and the boost circiut.

 

I've also been told that the 48's valvebody is designed to hold a lot more pressure thus they can up the pressure much higher for better holding.

 

I've never seen anything to support that, any of the 48 trucks that I have seen have not had one psi more pressure than the 47 trucks???

 

I'd send an email or pm to one of the tranny guys here. Many folks have bought trannys from shops that post on DTR. I am sure one of their tech guys could answer your question in detail. With trannys I wouldn't assume anything, I'd go right to a pro and see what he says.

Try here: www.gbtransmissions.com

 

I took the 47 out of my truck and haven't looked back. It made the same amoutn the my new 48 does at idle - however at WOT the 48 pushes much more pressure. My truck drove like a totally different truck by just installing a 48re. MUCH MUCH more hold in all gears not even taking into account when I flip that lock-up switch - she's locked.

 

So you put a gauge on this and can verify the presures? And you are talking stock to stock? I have seen NO difference in stock units with a gauge.

 

Powerstrokin is talking about pulling a STOCK 48re VB and replacing it with a MODIFIED 47re. The 47re modified will make more pressure than a stock 48re valve body. Expanding on what McMopar already stated, How much pressure depends entirely on who built it. Most tranny shops do not use the full pressure available from a 47re vb.

 

CarcajouCummins did Powerstrokin get such a good deal on the modified 47?Why wouldn`t he have just modified his 48?I am lead to believe that the 48 is a much stronger tranny.When the 03`s with the HO were about to be released they found that the 47`s could not handle the 305 hp that the HO produced,so they replaced it for the 48.So why not mod the 48 and have a MUCH,MUCH better tranny,then just having mod`ed 47.
Just wondering?Maybe when and if he does put that 47 in and he has his 48 laying around collecting dust maybe he`ll can ship it to me ,cause could sure use a better tranny.lol.

 

But which valve body (47RE or 48RE) is a better foundation for upgrading?

 

Kids toy, he is only changing the valve body, so he will still have the good 48 parts. There are alot of internal HD parts which make the 48 more durable. Planetaries, Sun shell, pump, etc. These parts will all go into a 47, but some need to go with their "unit" assembly.

XLR8R, The 48 valve body is a better foundation, but it is not alot different. than a 47.