Thread: th350 blues

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welp I lost high gear in my one and only daily driver....
It's a silverado with a 427 bb..
I just had a few questions before I start spending cash, cause I'm considering going with a th400...

-Will the all the shaft spline counts be the same as in a th350?
-Is a th400 short tail = to a longshaft th350?
-should I even invest in a th400 to begin with?
-has anyone had any experience with "raptor blood" atf?
-should I go with an integral or external atf cooler or both??
-does anyone want to donate me a transmission or give me a good deal on one?

after i get done beating my car with a hammer you can have the t350

Originally Posted by zero_presence

welp I lost high gear in my one and only daily driver....
It's a silverado with a 427 bb..
I just had a few questions before I start spending cash, cause I'm considering going with a th400...

-Will the all the shaft spline counts be the same as in a th350?
-Is a th400 short tail = to a longshaft th350?
-should I even invest in a th400 to begin with?
-has anyone had any experience with "raptor blood" atf?
-should I go with an integral or external atf cooler or both??
-does anyone want to donate me a transmission or give me a good deal on one?

th400 use the same torque converters but not drivshaft yokes th400 is bigger.
the th400 is longer than a th350 but in your case a long th350 is longer than a short th400 an you would need to find a driveshaft or have one made.
what do you mean by internal cooler? the stock one inside the radiator? if so run both use the stock cooler in the radiator but add another inline cooler for extra cooling going back to the tranny. but as far as atf iv'e always used valvoline an B&M parts

I've never used a trans cooler for a daily driver. But then I've never had high HP in a dialy driver either.

Ok on your TH350 Long tail it's 30 11/16" in overall Length . And the Front edge to the mount is 20 3/8" . Now on a TH400 short shaft . It's 28 3/8 overall Length . And the Front edge to the mount is 26 15/16" . This means you would need to move your crossmember back . That should not be a problem . And many Chevy trucks came with TH400s and the frames are drilled for this . Now the biggest thing you would need is a Longer driveshaft with a TH400 yoke with the bigger tail shaft splines . Also the Filler tube is different then the TH350 . One other trans that you could use is the . 700R4 That one is 30 3/4 overall Length and the front edge to the mount is 22 1/2" . Also it uses the same drive shaft yoke splines as the TH350 . And the drive shaft length will fit from your TH350 to the 700R4 . I do not think this one is good for you because they are to high priced . I do think with you being on a budget . It would be best to go to a Junk yard and find a clean Long Tail TH350 . I had a 1974 GMC Pick up that burned out the TH350 . I bought one for $100 bucks at the Junk Yard . Then I changed out the Filter and front + rear seals . Picked up some new O-rings for the filler tube and kick down cable . Filled it up with Ford Type F fluid . The ford fluid will make the plates grab more . Many Trans guy here run it in there builds . And your good to go . Now I would not beat on this trans . It will work fine (To and From ) . Later when you have the Fun-es . Do the TH400 Swap .

thanks I appreciate the info

Originally Posted by tango

Ok on your TH350 Long tail it's 30 11/16" in overall Length . And the Front edge to the mount is 20 3/8" . Now on a TH400 short shaft . It's 28 3/8 overall Length . And the Front edge to the mount is 26 15/16" . This means you would need to move your crossmember back . That should not be a problem . And many Chevy trucks came with TH400s and the frames are drilled for this . Now the biggest thing you would need is a Longer driveshaft with a TH400 yoke with the bigger tail shaft splines . Also the Filler tube is different then the TH350 . One other trans that you could use is the . 700R4 That one is 30 3/4 overall Length and the front edge to the mount is 22 1/2" . Also it uses the same drive shaft yoke splines as the TH350 . And the drive shaft length will fit from your TH350 to the 700R4 . I do not think this one is good for you because they are to high priced . I do think with you being on a budget . It would be best to go to a Junk yard and find a clean Long Tail TH350 . I had a 1974 GMC Pick up that burned out the TH350 . I bought one for $100 bucks at the Junk Yard . Then I changed out the Filter and front + rear seals . Picked up some new O-rings for the filler tube and kick down cable . Filled it up with Ford Type F fluid . The ford fluid will make the plates grab more . Many Trans guy here run it in there builds . And your good to go . Now I would not beat on this trans . It will work fine (To and From ) . Later when you have the Fun-es . Do the TH400 Swap .

can't always rely on a junk yard though i went through 6 of them before getting a good one well it wasn't good but it worked it didn't have second gear but all the others didn't work at all or slipped plus spending tons of money on tranny fluid but for $100.00 you can get a th350 rebuild kit from Napa rebuilding them is fairly easy just keep the parts in order as they come out an have patience with the lip seals during reassembley. if you cut a lip seal it'll slip. but you will also need tools to do it, snap ring pliers to open an take out C-clips an a spring compressor for the clutch packs I get all my TH350 stuff from older guys at napa that know what you need an what your talkin about. to many younger guys that are like umm uh no we don't have that. but the master rebuild kit you want has all the seals an gaskets with the clutch discs an metal discs for around $80 - $100 for a th350 1968 - 1980

my dad is trying to talk me into the 700r4, but I have had allot of folks tell me they won't last behind a big block. I also plan on doing some work to the motor, just to squeeze a little power out, such as a cam and lifters and head work, stuff like that, what do you guys thnik?

I have seen more 700R4 Transmissions in the junk yard then TH350 this year . And some painted up rebuilt ones . I never had much Luck with them . And if you have one built up for a HP build . They are like $1200 bucks . But they do have that Low 3.07 first gear and the OD high gear . With the 700R4 you Could run a 3.42 rear end gear and have the best of both Low-end and top-end Power .

but will my 427 tourque it to death? if i get one it will be a stock reman. I don't want it to go out within the next 3-4 years....

If your 427 is not to built up . It should be ok . I have seen some real built up Third Gen Camaro's with 383s and stock 700R4s . Also some GM 454 trucks had them stock . Try to find a nice clean used one .

ok, cool man i'll put some thought into it... If i get one it will be a reman from the partshouse with a warranty

could always rebuild your TH350 also an replace its week links.
in my opinion the 700r4's are junk plus need wiring to get the overdrive. but ods are 50/50 on finding a good tranny from a junkyard plus 700r4 valve body valves like to stick. motor revs sky high before it shifts. i would say a TH350 is stronger than a Th700R4 plus your truck is set up for a TH350 so why not stick with it but improve it to handle hard abuse with B&M parts

get the hardened 2nd gear sprage and the "blue" clutches and the extra clutch in high gear you should be good to go.

Yeah i think im going to stick with the th350. I found a guy out here who the guys at work say has great parts. He sells an OEM overhaul kit for $89.30 or a HP kit for $143.94. Also I can get a reman pump for $65.00 and a converter for $50.00. Sounds good to me what do you guys think?