lift question

[polish pete]

hey guys new here and getting more familiar with these trucks, just picked up a pretty clean 80 gmc k20, its a pretty heavy duty truck, 4spd small block, 14bolt ff.

so my question is what kind of lift can i get away with without having to clock the transfercase, i was looking into a rough country 4in lift to start and then continue on with other pieces, can you guys help me out?

[Grim 82]

You could do any amount of lift you want without clocking the case. Clocking the transfer case just brings up the front pinion and increases clearance.
Welcome to the site

[polish pete]

well when you lift any truck the angles in the driveshafts start to become more extreme, so thats why people clock them, is what i thought was the purpose.

[Grim 82]

Typically when people clock their transfer case it's to raise the front pinion and give overall clearance for the case and the front driveshaft, which actually makes the driveshaft angle more extreme. I guess you could counter clock the case to make the angles less severe, like in a monster truck, but if you're just considering a 4" lift you will be good to go with leaving it in the stock configuration.

[4x4orbust]

you can clock a t-case any way you want.  most off roaders clock them up  to increase belly height clearance.   some (mostly mud guys) clock them down to decrease driveline angles.  both work fine.  

you do not have to clock your t-case with a 4" lift.

edit:  great minds think alike grim....

[Irish_Alley]

you don’t have to clock a 6" but someone with a blazer is running into problems with a 6" lift but iv seen 6" in trucks the only problem is the front shaft tends to be stretched out a bit

[polish pete]

so if anything even with a 6in lift, you would want to get a new front shaft made or the old extended just to be safe correct?

[4x4orbust]

yup, front  definately needs to be stretched.   maybe the rear too on a 6" lift.

[polish pete]

great thats just what i wanted to hear, thanks guys really helpful.

[Irish_Alley]

Most places will tell you your ok with a 6 but as someone found out on here he wasn't and the font usually fit but have so little contact with the splines they wear fast the you have a lot of slop. And its easier to shorten a shaft than to make one longer. Since I have a sm465 the front shaft is shorter than lets say a th350 so I took that shaft and cut it down and made it a couple inches longer than my 465 shaft