1963 Avanti automatic driveshaft, same as a Lark?

[Canuck E]

Hi all. Looking for some help in getting a driveshaft. Will a Lark V8 automatic drive shaft work in a 63 Avanti? Any other ideas on what would work? Thanks in advance!

[A0136]

Canuck E

Yes and no.  The earlier Larks and later Larks have slightly different lengths. Later Larks (Crusier) had a longer wheelbase and longer driveshaft. Larks also used 2 different u-joint types (spicer and mechanics) so the drivelines can be the same length but not be the same.  
The 63 Avanti with automatic (powershift) uses a driveline that measures 46 9/32”  center to center of the u-joint holes. The Avanti driveline used spicer u-joints.

So some 62,63 and 64 Larks with automatic’s use a 46 9/32 length driveline. If one of those has the spicer u-joints it would fit. I don’t know if the tube size and thickness is the same or different. 
A driveline from a 3 speed OD car or longer wheelbase with spicer u-joints could be shortened and have the yoke changed. 
Steve 

[mfg]

The difference in wheelbase lengths on the Lark is negligible (1/2”)… A driveshaft from any shorter wheelbase Lark with auto trans will work…(109–109 1/2” wheelbase)

You will find a driveshaft from a Lark ‘6’ is smaller in diameter and ‘thinner’ walled, but it too will work in a pinch!

[A0136]

My experience after ruining 2 V-8 transmissions is that the 6 cylinder driveline is about 1” longer than the V-8.  
be sure to measure any driveline you use and don't install one that is longer than it should be.  
Steve 

[mfg]

1 hour ago, A0136 said:

My experience after ruining 2 V-8 transmissions is that the 6 cylinder driveline is about 1” longer than the V-8.  
be sure to measure any driveline you use and don't install one that is longer than it should be.  
Steve 

Hmmm!… Did you use a  driveshaft from a ‘63 or ‘64 Lark ‘6’ two speed automatic?

That could account for the 1” longer shaft.. since a pre ‘63 cast iron Flightomatic  ‘6’ auto trans would use the same length shaft as any V8 built on the 109–109 1/2 wheelbase….including Avanti…. Ed

PS… Steve’s idea of measuring things up is a very good one though!