Swaps are swaps

[bucketead27]

Hey guys man this site is full of knowledge!! Anyway Im running an 83 k10 with th350/np203, I do not like that case, anyways Ive got a lead on an np241 Im really interested in. Hopefully all I have to do is adapt the th350 to make it as long as a 700r4, change output shafts use the adapter thats on the np241 now and get the driveshafts modified to fit. Sounds pretty straight forward im going to use the cross member that the np241 was using as well. Can you guys think of anything else Im missing here?? Im fairly new to 4x4's but I can build one heck of a race car. Thanks, Jordan

 

[diesel4me]

I put a NP-205 in a 77 GMC I had that originally had a NP-203 coupled to a TH-350 tranny (4x4 stock version)...I used the TH-350 adapter to the NP-205 that was on it from a '72 K20 4x4...the front driveshaft was then too long,but the rear one still fit OK..

I think a NP-241 from a 700r4 will have the right spline count on the input ,27 slpines like a TH-350 ,and the 700r4 adapter should have the same bolt pattern in the tail end as a TH-350 so as long as the output shaft is the correct length,I think it should all bolt up.....not sure if the crossmember will have to be changed or not though..

I'm sure someone else here will correct me if I am wrong...

 

[sweetk30]

you need to get a 700r4 to th350 swap kit . this will get you the correct length tail shaft and spacer to make it all bolt up .

or you need to test fit stuff and do custom matching if you do not want the spacer .

drive shafts need reworked for length for sure and also 203 full time case was bolt on yoke rear shaft . 208-241 are slip yoke shafts.

th350 with 203 OR 205 used same length output tail shaft . 208-241 used different . and 241 was never offered on th350 but same spline count input as th350 tail shaft of 27 spline.

also finding rare th350/208 will be kind of fun .

but little reading will get you the parts you need.

 

[wasted wages]

I'm pretty sure I have a 350/208 on the shelf in my shop as well as the
350/700r4 spacer..... Let me know if you need any pictures or measurements...

 

[bucketead27]

Thanks guys I appreciate the swift answers and thoughts. Im almost certain that block of aluminum or spacer is almost 1" thick, Im not sure though but Summit wants almost 100 bucks for the darn thing. Ive done a bunch of research but it seems like if I have the right adapters and have some driveshaft work done is pretty much a bolt up and go type swap. Im also swapping out the tired 305 for a hot 327, should be very interesting. Im excited for it and as soon as Im done I will post up pics. Basically im taking the fuel system, ignition system, and motor out of my s10 and putting it in the K10. I dont plan on romping on it often, hopefully that tcase will hold up. Its a pavement queen anyway.

 

[sweetk30]

its around 1.75 thick if i recall on the spacer.

what fuel system from s10 ? and size motor on it ?

 

[bucketead27]

Well I pulled the entire stainless braided 8an hose Holley blue pump regulator and Holley 650dp out of the s10. Also got the msd 6al box and pro biIlet dist to run the thing. Basically I'm pulling the motor and all components and transplanting it in my k10.

The motor is a 327 bored .30 out with flat tops. Rotating assembly was balanced with 461x heads w2.02 1.60 valves with guides and roller rockers. i should have went with a solid cam to get the revs out of the motor but it's got a hyd comp 292 dur cam. It sounds real nice somewhere around 475hp at the top and 380lbs torque. Not a very good motor for torque but all the hp I could ask for. It should give my truck a little more bite with the bark.

 

[bucketead27]

And on another note, how much tailshaft do I need hanging out of the rear of the tranny to engage the splines on the 241?