1984 k30 manual to auto swap question

[DQ81]

Hi.

I've got a 1984 Chevy CUCV (K30) that was converted from a 6.2 diesel to 350tbi out of an '87 truck or van.

It's got the stickshift with L,1,2,3 and I believe the NP205 transfer case (it has the 2wd option) I'm fairly certain it's a factory stickshift truck (trans tunnel inspection panel, stock pedal cluster etc. etc.)

My clutch is toast and the 350 doesn't like the gearing the stick has and I'd prefer an auto anyway. I wanna put a TH400 in there.

Anyone know what gearbox I've got in there now or what would have been stock or where to find the numbers?

Will a TH400 bolt right up and fit length wise to the TC?

Obviously I'll need a flexplate but I should be able to use the existing flywheel right?

I'm hoping I can just swap em out and do the obvious: floorshifter, external transcooler and be done. Not have to mess with reposition the TC or mess with driveshaft lengths...

tia

[ozark]

You should have a sm465. A turbo 400 wont go in place of the 4 speed without changes. The transfercase has different spline count between the two, The transmission adaptor between the two transmissions is different, the driveshafts are different lengths. Because the 400 is longer than the 4 speed so you will have to move the transfercase back. The transfercase shifter is different ( I found out on my own the other day) between the two transmissions. Flywheel and flexplate are different you will need a flexplate for the 400.

[DQ81]

Originally Posted by ozark

You should have a sm465. A turbo 400 wont go in place of the 4 speed without changes. The transfercase has different spline count between the two, The transmission adaptor between the two transmissions is different, the driveshafts are different lengths. Because the 400 is longer than the 4 speed so you will have to move the transfercase back. The transfercase shifter is different ( I found out on my own the other day) between the two transmissions. Flywheel and flexplate are different you will need a flexplate for the 400.

That kind of sucks. What I was afraid of. Thanks for the info.

So long story short, if I want to switch to auto, I'll need the TH400/TC and a set of driveshafts... in other words, everything.

I'll need a flexplate obviously for the torque converter but why a different flywheel?

[Zane M]

In relative terms, it is easy, but not as easy as you want it to be.
If you were planning on going used, try to get a complete transmission/tcase set up.
In a perfect world you find someone that is parting out a truck and you could get every possible piece you will need in one stop.

[andrewmp6]

I think he ment take off the flywheel and put on a flexplate,A flywheel is for a stick a flexplate is for a auto.

[DQ81]

Originally Posted by andrewmp6

I think he ment take off the flywheel and put on a flexplate,A flywheel is for a stick a flexplate is for a auto.

oh right of course... missed that. cheers

[GM72K10]

Originally Posted by DQ81

Hi.

I've got a 1984 Chevy CUCV (K30) that was converted from a 6.2 diesel to 350tbi out of an '87 truck or van.

It's got the stickshift with L,1,2,3 and I believe the NP205 transfer case (it has the 2wd option) I'm fairly certain it's a factory stickshift truck (trans tunnel inspection panel, stock pedal cluster etc. etc.)

My clutch is toast and the 350 doesn't like the gearing the stick has and I'd prefer an auto anyway. I wanna put a TH400 in there.

Anyone know what gearbox I've got in there now or what would have been stock or where to find the numbers?

Will a TH400 bolt right up and fit length wise to the TC?

Obviously I'll need a flexplate but I should be able to use the existing flywheel right?

I'm hoping I can just swap em out and do the obvious: floorshifter, external transcooler and be done. Not have to mess with reposition the TC or mess with driveshaft lengths...

tia

NO CUCVS EVER came with a factory stickshift. They were all TH400s. Good Luck with your conversion though

[ozark]

Too bad your not closer I have everything you will need to do your conversion.

[DQ81]

Originally Posted by ozark

Too bad your not closer I have everything you will need to do your conversion.

too bad indeed. I've since sold the truck to get my Blazer finished.

thanks to all.

cheers,