Question about drive shaft

[ivorton74]

Im getting my 5.3/4L60 swap from my old 74 c10 swapped into my 83 c10. My buddy tried fitting the driveshaft that we had made for the 74 but turns out its too long. The engine n tranny are sitting a bit further back in the engine bay of the 83 so thats one reason why.

However the 74 was lowered when we measured to have the driveshaft made n the 83 isnt lowered yet. So my question is does it make a difference if the truck is lowered or not when measuring for a driveshaft? Im taking it to get it shortened tomorrow n also have to swap out the u joint since the 83 has a 10 bolt rear end.

Forgot to mention that the yoke is all the way inside the transmission

[mongocanfly]

lowering a vehicle can affect driveshaft length but it is very minimal. ..not enough to need changed as long as you have adequate yoke slip at the trans end

[scoot_mcgrute]

Sounds like the truck is still in the air?

If that's the case, get it on the ground or have the axle sitting on jack stands to get a more accurate measurement.

[ivorton74]

Took it to a machine shop n had it shortened by 4 inches...im praying to God it fits

[mongocanfly]

you didn't measure?...

[87chevy.com]

Originally Posted by ivorton74

Took it to a machine shop n had it shortened by 4 inches...im praying to God it fits

A machine shop, or driveshaft shop?
Clint

[ivorton74]

Originally Posted by 87chevy.com

A machine shop, or driveshaft shop?
Clint

Yeah its actually a driveshaft shop lol...took it to Midwest Welding and Drive in Fargo ND.

@mongo...my buddy did some measurements yesterday and decided to have shortened by that much.

The guy at the driveshaft shop told me that the driveshaft was too way long for a steel driveshaft and he's surprised it didnt snap in half already. I told him It was custom made for my old truck...he said they should have made it from aluminum instead. Anyone has any idea what he's talking about? I dont know anything about this stuff. I know some of these truck came with 2 piece driveshafts though.

[mongocanfly]

haha..I thought you just guessed at how much to cut...
is your truck lwb or swb? lwb should be 2 piece..
new trucks do have aluminum driveshafts..I like steel though..
the 2015 camaro ss I got my ls3 out of has a 2 piece driveshaft..go figure...whole thing isn't 5 ft long...and its steel

[ivorton74]

My 74 and 83 are both long bed trucks and they both had one piece driveshafts. When we did the first swap the driveshaft was actually too short...so we had to get one made.

[mongocanfly]

my 81 lwb has a 2 piece d-shaft. .I made a swb out of it..

[87chevy.com]

Research driveshaft critical speed... it can only be so long at a certain diameter at a certain rpm unroll it turns into a wadded noodle. Aluminum can go bigger diameter and thus longer. Just like all bmws, and the camaro, 2 short driveshaft instead of 1 pc means higher critical speed, smaller tube..
Clint

[ivorton74]

Yup..he did mention something about 3500rpm and the diameter of the driveshaft. My e39 bmw does have 2 short ones if i not mistaking

[mongocanfly]

if your like me and your right foot is bigger than your left one..I'd listen to your driveshaft man...you sure don't want it coming loose on ya when you hammer it..

[ivorton74]

Well the driveshaft fit without any problems. Took it on its first drive and entered a burnout contest in it. Already not liking my 2.73 gears...need lower gears like 3.42s or something

['68 C10]

Ran into same problem with my '72. The factory two piece was 4" too long, had a TH400 yoke, shot UJoints, and suspect carrier bearing. Ended up being cheaper to build a one piece aluminum shaft rather than modifying/rebuilding the two piece.