have a cuple of questions

[lifted 75 k5]

ok i have a 75 lifted chevy blazer that has a sb 350 turbo 350 trans and a np 203 case but i want to change the case to a np 205 and change the rearend to an 8 lug and drop the 6 lug but i am sure that i need a new drive shaft and i want to do it all at once so can i buy the new shaft now and it will bolt up to the new rearend or should i wait and have everything ready and measure and get the new shaft made after i install the new rearend and t case

[FormerMember]

Originally Posted by lifted 75 k5

ok i have a 75 lifted chevy blazer that has a sb 350 turbo 350 trans and a np 203 case but i want to change the case to a np 205 and change the rearend to an 8 lug and drop the 6 lug but i am sure that i need a new drive shaft and i want to do it all at once so can i buy the new shaft now and it will bolt up to the new rearend or should i wait and have everything ready and measure and get the new shaft made after i install the new rearend and t case

Have the t-case and axle assembles in, then measure for shafts. You can probably modify your existing ones, unless they're toast.

[Big68]

You could get measurements of the driveshaft of someone who has the exact same setup as you're looking for and it still might not be right for your application. Best way is to measure it once you've got all your new parts in.

[lifted 75 k5]

ok and is one shaft better or one that is like a 2 piece

[FormerMember]

Originally Posted by lifted 75 k5

ok and is one shaft better or one that is like a 2 piece

Depends on the angles in your drivelines.

Typically, you'll get one shaft, unless it's a really long one.

One shaft is also cheaper.

[lifted 75 k5]

so is a one piece also stronger

[FormerMember]

Originally Posted by lifted 75 k5

so is a one piece also stronger

Based on it being simpler, with less moving parts, yes.

[lifted 75 k5]

ok and to get the measurments i need to do something like a triangle correct from yok to yok directly and from yok down to the heighth of the other yok and straight across from that point correct and if not how

[FormerMember]

Originally Posted by lifted 75 k5

ok and to get the measurments i need to do something like a triangle correct from yok to yok directly and from yok down to the heighth of the other yok and straight across from that point correct and if not how

I measure from the center of the yoke to the center of the yoke. Straight line.

[lifted 75 k5]

ok then angles in the drive lines you said something about which one to go get(one piece or two) depending on angles how do i know or should i just get a one piece for sure

[74 C-30]

depends on if you lifted it..one piece is fine up to 6" i assume

[LONGHAIR]

The two-piece design is basically about length. As the shaft gets longer it also has to increase in diameter to maintain it's "torsional rigidity". Meaning that if it is too long/skinny....it will twist, rather than drive the pinion.
Having a two-piece shaft cuts out part of the tubing, making each section shorter.

I have never seen a two-piece driveshaft in a Blazer, it is just not long enough to ever worry about it.

[Hoods69BadBowTie]

^I gotta agree I have never seen a 2-piece drive shaft in a Blazer yet. I think the easiest way to measure too is from yoke too yoke but I may be wrong.

[lifted 75 k5]

but the two piece would be better for crawling because it has room to move as the body twist or articulates so the 2 piece shaft therefor would be better for crawling and out playing on trails right

[LONGHAIR]

The clearence that you might gain in the middle of the shaft could be helpful on a LBW truck, on a Blazer you are just gaining too much angle at the lower joint. The more lifted....the worse this would be.

[BIG HEAD]

wait until last on the drive shaft. longhair is right own the drive shaft being one piece in the blazer. because of the short wheel base.

one other thing that you may want to think about when having your shaft built is the joint size. since you went to an 8 lug rear it may have a larger joint. i like having all the same size joints on my rigs. it can cost a little more for matching yokes, but alot less agrivating. one spare joint fixes all. i like to keep it simple.

[lifted 75 k5]

oh ok thank you for all your help it was extremly helpful