t-case/350 trans combo

[KORNBREAD]

what t-case's out there will bolt right up to a 350 turbo trans?? Im getting a 79 Chevy 1/2 ton that someone put a 700r4 in and fried it. I want to go back to a 350 turbo but i dont want the 203 case and finding the 205 with adapter for the 350th is harder to find and pricey.

[J.C.]

350s had a 208, 81 was the only year i think. being only 1 year, i think they would be harder to find? you could put a set of lockouts on the front depending on what axle it is, if ya used a 203.

[KORNBREAD]

Yeah the truck has front lockout already. I dont want to run the 203 because there so damn heavy and (not a huge fan). Im restoring this truck when I get and its not going to bogged ( i will play some here and there) so a 203 would be fine but i just dont like them. I was hoping to do a lighter case like the 208 or so.

[Captn. J]

208 or the 241

[KORNBREAD]

the 241 will bolt up?? what year 241's

[7387chevynut]

208 or 241 will NOT bolt right up...............because your 350 turbo is the 1970-1980 style..........meaning it has a SHORT rear tailshaft, and it was only meant to work with the 203 (which had a thin adaptor plate)..............or the NP205 (which used the thicker adaptor...but with a splined coupler inside of it).

GM did offer the NP208 behind the 350 turbo, but it was only in the 1981 model year.........and GM had to modify the tailshaft of the 350 to make that work............AKA>....they made the shaft longer..........so it would run through the adaptor.....and straight into the T-case..............this design did away with the idea of a (thin) adaptor plate............or using a (splined coupler) inside the adaptor housing.

Now you can modify a 1970-1980 350 turbo to bolt up to a 208 ( contact Mudbuster on here, he's done this already). By using a 350 turbo NP203 adaptor, with a little welding, and drilling some extra holes.....it will work. The other option you have......is getting a 2wd 350 turbo shaft....which is longer, and have it cut down to length, or keep it as is and run a aluminum spacer in between to compensate for that extra shaft length.

Other options......are     KEEP your 700R4......which should already have the NP208 behind it.......and have it rebuilt.......and have the advantage of a lower 1st gear of 3.06 and Over Drive.

Or get a 203 (very common to find) and install a part time if doesnt already have one.

Or find a NP205 for your 305 turbo, which 1970-73 (74-75 )  had fixed yokes, or the 1980 version which was slip yoke rear, and they tend to be pricey 150/250 for complete set up.

I think your cheapest route.......is to have (Mudbuster) make up a adaptor plate for you......using a 203 adaptor plate from a 350 turbo/203 combo.

[Captn. J]

like he said above mudbuster gave me one of the adapter that he made to fit a 208 behind a 350 that orginally had 203 .... i m in burton and u re welcome to come n look at my set up...  it use the 203 adapter   few holes drilled and  it works for me

[Captn. J]

it all also depend the tailshaft of your 350

[KORNBREAD]

I want to run a 700r4. I keep getting told I need a switch to hit to lock up the converter, which makes no sense because thats what the detent cable is for. All my older 80's carbed chevys never needed a switch. they had the detent hooked up to the carb. am I missing something?? 

[Captn. J]

u re confusing us   on  top u said u wanna  run 350  and now u re saying u wanna run a 700r4?

[KORNBREAD]

I wanted to run the 350th but if I cant find the t-case I want with out chasing down all these special adapters then ill be going to a 700r4 so I can have the light aluminum t-case. So there thats straightened out and back to anyone who can help with the detent/rv cable for the 700. lol

[J.C.]

the switch you are talking about "locks" the converter in for better gas mileage. detent cable controls when the trans downshifts. in the electronic trans they use the throttle position sensor, TPS, instead of a cable. mudman could rebuild that trans quick and cheap... thats another option.

[RIP_K52007]

the 700r4 is suposed to have the convertor locked at cruising speed, and without the lock they do run hot, not really good for them. They work, just shorter lifespan.

i'd drop a nv3500 in it and be done with it

[RIP_K52007]

http://wegotmud.com/forum/index.php?topic=69149.0;topicseen

[KORNBREAD]

I know what the lock up dose on the trans, but I dont remember my older 80's chevys having that plug. I remember the detent/tv cable but thats it. (God its been a long time sense ive messed with the 700)

[KORNBREAD]

http://wegotmud.com/forum/index.php?topic=69149.0;topicseen

Thanks man but $250 is a lot of cash for a "not sure how it runs" trans.

[J.C.]

http://wegotmud.com/forum/index.php?topic=69149.0;topicseen

Thanks man but $250 is a lot of cash for a "not sure how it runs" trans.

ill sell ya a 700 core for $50. and i guarantee it wont work.

[KORNBREAD]

http://wegotmud.com/forum/index.php?topic=69149.0;topicseen

Thanks man but $250 is a lot of cash for a "not sure how it runs" trans.

ill sell ya a 700 core for $50. and i guarantee it wont work.

[KORNBREAD]

Think Im just going to run the 350/203 set up. More I think of it makes more sense. Trucks just going to be a part time dd/work horse. thanks for the help guys!

[Squirell]

Take a 350 to mudman and tell him to put the 208 kit in it. You will get a 4 in aluminum spacer and then just need the adapter that comes on a 208 and by.doing it this way you drive shafts stay the same length