need some trans advice

[jimmy101]

Which trans do you think would be best for my project?  It is an 87 full size chevy with a small block. I have gmc face loaders with 6:17 gears.  I am going to install a divorced ford 205 t-case to help with the drive angle. I have on hand a th400 mated to a 208 t-case and i have a  th350 mated to a chevy 205 t-case along with a ford 205 t-case.  My thinking is.. I wont be able to use what I have as far as trans and t cases go.  So I am going to have to purchase a two wheel drive trans, make a short driveshaft and use my ford case.  Question is.... do I use a th350 or use the th 400.     tires are 18.4-16.1  and motor may at the most have 450 hp. Thanks in advance for any advice.

[J.C.]

Th350. Less parasitic loss. Takes more power to turn the stuff inside a 400 than a 350. If you had 600+hp I'd say go for the 400.

[jimmy101]

Th350. Less parasitic loss. Takes more power to turn the stuff inside a 400 than a 350. If you had 600+hp I'd say go for the 400.

ok, that makes sense to me. What do you think about using a two wheel drive trans instead of a 4x4 trans. I dont know much about the tailshaft housings except that there are long ones and short ones. I dont know if you can make a 4x4 transmission  work with out having the t-case attacted to it. If It could, please let me know.

[xjs3667]

th400 with a 205 and twin stick it..... but if I were you Id throw the 400/208 in and run it till it blows and then throw the 350/205 in and figure out what is best for you, the th400 is way way stronger than the th350

[J.C.]

2wd for divorced case is your best bet imo

[jimmy101]

th400 with a 205 and twin stick it..... but if I were you Id throw the 400/208 in and run it till it blows and then throw the 350/205 in and figure out what is best for you, the th400 is way way stronger than the th350

i dont think either of the mated   combo's will work because of my pinion angle and they have the wrong drop. I have 12" springs and a 3" body on top of gmc 2.5 ton face loaders ( not rockwells). That is why I was thinking about using the divorced 205 and a two wheel drive transmission.  I must flip the front axle around which will put the pinion on the driver side. Both my gm t-cases have a passenger  side drop where as the other t-case I have is a divorced ford t-case with a driver side  drop.

[jimmy101]

2wd for divorced case is your best bet imo

Thanks J.C.  Thats kinda what I was thinking. I plan on installing  a monster rebuild kit, and before I spend  alot of cash I just wanted to hear from you fellas (and gals) that have been there and done that.

[xjs3667]

yep then id say go with a 2wd and divorced case then, they are pretty easy to hook up, and as long as your good with a welder you can make some brackets and braces for the t case. I dont think you would need to change trans cross member to switch to 2wd trans as long as its the same trans that was stock in the truck, the only difference is the tail shaft and the tail shaft housing.   ive never dealt with those axles but its probably not a good idea to flip it? unless you can do that with them with oiling issues? idk, plus wouldnt it throw the camber and caster off?  so sounds like you answered your question 2wd trans and divorced case

[xjs3667]

but you could always us a velocity joint to help with pinon angle too....

[J.C.]

The t case is reverse rotation, so you gotta flip it on the gmcs if you're gonna run a regular truck transfer case

[jimmy101]

The t case is reverse rotation, so you gotta flip it on the gmcs if you're gonna run a regular truck transfer case

yep. and there are some carrier clearance issues to deal with.

[BigFrank]

The t case is reverse rotation, so you gotta flip it on the gmcs if you're gonna run a regular truck transfer case

yep. and there are some carrier clearance issues to deal with.

only thing you have too flip is the 3rd member/pig/chunk/ carrier  whatever ya  want too call it lol  involves clearencing the  housing too clear the ring gear  pretty simple with a grinder

[jimmy101]

The t case is reverse rotation, so you gotta flip it on the gmcs if you're gonna run a regular truck transfer case

yep. and there are some carrier clearance issues to deal with.

only thing you have too flip is the 3rd member/pig/chunk/ carrier  whatever ya  want too call it lol  involves clearencing the  housing too clear the ring gear  pretty simple with a grinder

lol I just re read that. Yes, its the third member not the t-case  that gets flipped. It is because the 2.5 ton t-case does run reverse rotation so in order to run a regular truck t-case you have to flip the carrier/ pig/ chunk/member  (lol).  Good catch.

[84silverado]

I'd run the th350/205 combo for now till you can save up and build the drive train some more. I ran my sbc before I built it up more with my th350/205 and even clocked it so it sat vertically to help with the driveshaft angle and I ran it like that for over 2 yrs with no problem. And shifting your case is easy, heat the shifter up with a torch, bend it up through the original shifter spot in the cab, it'll be just like a normal truck. I ran this setup with 18.4-26 R-2's also with ease.

Also p.s. Take the front output from the divorced ford and put it in the th350/205 combo that will also help with the driveshaft angle because then your front output will be a yoke and 32 spline.

[J.C.]

Lol I didn't mean flip the case, only the chunk (3rd member)

[BigFrank]

Lol I didn't mean flip the case, only the chunk (3rd member)

I  knew  what ya meant  lol  but ive seen a couple people flip the whole axle around     I have a extra gm-1 t case  ya don't have too weld anything just a bolt in the range selector rod  too keep it in 4wd   could run the  th 350/ 205mated into that   no messing with flipping the axles

[BigFrank]

http://i889.photobucket.com/albums/ac94/Big_Frank_2010/P3091288_zps8322c74b.jpg?676        that's what they look like

[jimmy101]

   hmmmm   lots of choices .  thats a good thing.   350/205 into military t-case..... very do-able.   Soooo..   instead of a two wheel drive trans...it would be better to just add a military case? What do these things weigh? 

[BigFrank]

pretty close too what a  205 does

[jimmy101]

Also p.s. Take the front output from the divorced ford and put it in the th350/205 combo that will also help with the driveshaft angle because then your front output will be a yoke and 32 spline.

nice tip. I like it .  thanks

I have alot to think about now.  I like all the idea's

Big Frank  ??  You have me thinking about this two case idea. For the weight gain I am not sure how much I would benifit  from doing this.   also 4:1 seems too low.  idk  I think I would be better flipping the  chunk and running a regular t205.