I have a 91 k5 with a np272 i have a np205 avalible. would this be a fairly easy swap other then new shafts for some extra beef.

Do you mean you have a np 241?

either way the answer is no. there is more to do to put a 205 behind a 700r4/4l60 (im assuming). either a shorter output shaft on the tranny, or an spacer and the 205 adapter, or modifing the factory adapter. im fairly sure it has to be one of those options. not to mention little things like speedo and shifters and probably trouble with the VSS.

Depends on what the t-case used to be behind. They either have a weird, I think 9 bolt, pattern and a round 6 bolt pattern. The inputs also widely varied in spline count and either male or female. I'm not sure about shaft length tho. Since your np241 has a slip yoke tail end, you'l need a new driveline yoke and possibly lengthen it. Since your truck is EFI, I assume, you'll need a VSS adapter to adapt the mechanical speedo to an electric output for the ECM. If you're not going to wheel it hard, I wouldn't put forth the effort. I have a burban, SAS'd, that weighs 7,200lbs with a 241 and it handles fine, but I don't rock crawl with it.

Depends on what the t-case used to be behind. They either have a weird, I think 9 bolt, pattern and a round 6 bolt pattern. The inputs also widely varied in spline count and either male or female. I'm not sure about shaft length tho. Since your np241 has a slip yoke tail end, you'l need a new driveline yoke and possibly lengthen it. Since your truck is EFI, I assume, you'll need a VSS adapter to adapt the mechanical speedo to an electric output for the ECM. If you're not going to wheel it hard, I wouldn't put forth the effort. I have a burban, SAS'd, that weighs 7,200lbs with a 241 and it handles fine, but I don't rock crawl with it.
the planetaries in a 241 acually have a higher torque spec than a 205. but thats just the planetaries. it doesnt account for the chain or the slip yoke or especially the alluminum case.

the planetaries in a 241 acually have a higher torque spec than a 205. but thats just the planetaries. it doesnt account for the chain or the slip yoke or especially the alluminum case.

I agree

Is the swap easy? No. The 241 in your K5 is a pretty strong case with 2.72 low range. The 205 is about as strong as they get but unless you put a Lomax 3 to 1 together the 1.96 low range sucks.

i'd leave the 241

make damn sure
1. that the case does not get hit by a rock (it will shatter) put a good skid under it
2. the driveshaft slip does not bottom (it will destroy the case)
3. the d-shaft yokes do not angle out putting the case in a bind

it's a good t-case if you protect it

Frank

Im not sure the tag on the case says 272 but i thought it was a 241

Im not sure the tag on the case says 272 but i thought it was a 241

2.72 is the low range :D

either way the answer is no. there is more to do to put a 205 behind a 700r4/4l60 (im assuming). either a shorter output shaft on the tranny, or an spacer and the 205 adapter, or modifing the factory adapter. im fairly sure it has to be one of those options. not to mention little things like speedo and shifters and probably trouble with the VSS.

wouldnt the rare 205 from behing a th350 bolt up correctly? withoug any adapters, and the vss thing could be remedied by the adapter from jags that run. just another .02 from me

EDIT : but what are the chances he has that 205 anyways

the 205's from behind TH350's arent that rare. check out 67-72chevytrucks.com, they seem to crawl out of the woodwork over there. i also see a ton of them on ebay. definitely more common than anything 32 spline, but not as common as the craptastic 10 spline.

speaking of 10 spline, i'm pretty sure if you wanted, you could swap the 10 for the 27 spline gear, i think they use the same bearing.

but...

arent ifs transfer cases driver side drop? oops.

99.99% your np241 will do what you want it to do without any problems. it even has a better low range and a much higher factory input torque rating than the 205. iirc, for dd/light wheeling, 205's are unnecessary. not to mention you're gonna need to drop a ton of coin on this swap. its like an answer for a question that doesnt need to be asked.

the 205's from behind TH350's arent that rare. check out 67-72chevytrucks.com, they seem to crawl out of the woodwork over there. i also see a ton of them on ebay. definitely more common than anything 32 spline, but not as common as the craptastic 10 spline.

speaking of 10 spline, i'm pretty sure if you wanted, you could swap the 10 for the 27 spline gear, i think they use the same bearing.

but...

arent ifs transfer cases driver side drop? oops.

99.99% your np241 will do what you want it to do without any problems. it even has a better low range and a much higher factory input torque rating than the 205. iirc, for dd/light wheeling, 205's are unnecessary. not to mention you're gonna need to drop a ton of coin on this swap. its like an answer for a question that doesnt need to be asked.

yeah i picked up a 27 spline 205 like it was nothin. they still wont owkr, the 700 has a longer output shaft and that is why you need one of those methods i mentioned above. 10 spline and 27 spline do both use the smaller bearing.

and yes IFS trucks are drives drop, but a 91 k5 does not have IFS.

the only real problem with a 241 is the alluminum case. it cannot take a beating nearly like a cast iron 205 can. that, and the fact that it has a slip yoke. it would really be that expensive of a swap if you knew what you were doing. i think the most expensive method would be to get the shorter shaft for the 700. and it is only about $175 last time i looked. then you would need driveline work, but it can be done.