What are some downfalls of not running a spacer of my driveshaft of my 94 gt with a tremec 3550?

 

What do you mean by spacer? As driveshafts don't have spacers so you got me goin here... aha

 

the 5/8 spacer you run on the rear of the driveshaft to make up the difference in lengths of trannys

 

I have never ever seen a band-aid like that before.... Though if your shaft is indeed that 5/8" short you will need it or you're going to lost 5/8" of spline in your trans to transfer the power. I would personally just get the shaft lengthened for the 100 bucks that would cost though... I wouldn't want a spacer on one of the more fragile parts of the driveline

 

hmm... i'm trying to imagine how a spacer would work at the rear of the driveshaft?

i think someone is blowing smoke up your *** here. probably need a longer slip yoke, not a spacer.

 

http://www.latemodelrestoration.com/item/ST-5557705

thats the spacer. no smoke here

 

no smoke... I have said spacer, it eliminated my driveline vibration.

 

adder what kind of vibrations did you have i seem to have one at higher speed its like and intermittent vibration. and them sometimes at high rpms i have shifter shake. but the vibration is wierd because it vibrates stops vibrates stops vibrates stops and im going down the interstate at like 70

 

yea, it was around 70-80mph and would shake the whole car, 'cept the steering wheel.

put the spacer in and almost all of it went away. The rest went away when I set my driveline angle back to stock. Now i need to set pinion angle, and ill be done

 

It will set the splined yoke deeper into the transmission. Having it stick out too far will cause a wobble. I failed to correct this on a 383 Dodge Dart and broke the tailshaft of the transmssion at 120mph.

Since then I always run the yoke as close to the transmission as possible. 1/2 to 3/4" depending on the rear suspension design.

The ultimate would be a proper length driveshaft but it's $50 vs north of $200.