View Full Version : Turbo 350 tranny

03-10-2000, 08:24 PM
I have 74 GMC 3/4 4x4 with no powertrain and have the motor,and the tranny and the transfer case (NP-203) and all other relating stuff, the truck had a standard tranny before, so I was wondering the tranny<br>(turbo 350)and the transfer caseare bolted together, the tranny caseis cracked at the back were it is bolted to thetransfer case adapter on the top, and I'm was wondering if the tranny is good or is trashed.<br>thanx to all

03-10-2000, 09:06 PM
vance, i had a 3/4 ton with a 350/203<br>setup and it worked fine, i didn't even<br>know about the cracked tranny(same place<br>as yours) until i pulled it out. i just<br>tossed mine and got another, didn't want<br>to risk it. it seems to be a common thing<br>w/203 cases, their heavy and not well<br>supported. i also have a 77 1/2 ton <br>with the same running gear, i rebuilt<br>the trans recently, that trans probably<br>never cracked because the truck has never<br>been abused, i drive it sanely and it has<br>a 130,000 miles on it. i'd look for another<br>trans if i were you. if you plan on using<br>the truck hard, additional support may prevent future cracks or better yet swap<br>out the 203 for 205,their lighter and stronger and have no chain.good luck<br>4LOW

03-11-2000, 07:41 PM
I have a 78 k25 and it is equiped with a 400/th400 with np203, My tranny is not cracked and I know for certain that the truck has been used harder at times than others...<br>my father bought it new in 77 so I have known it its whole life and have put the majority of the 130,000 miles on it without a rebuild yet. I recommend the th400 tranny, never failed, fumbled or let me down yet and has held up under some pretty brutle abuse while I was in my teens....<p>-abe<br>