Turbo 400 in 72 Skylark

I am in the process of upgrading my 72 skylark to a 455/ T400 and have a long tailshaft T400.

My question is: since I have to shorten the driveshaft anyway, can I use the long tailshaft T400 or would I be better off finding what I need to change it to a short tailshaft?

Thanks

 

You will want to get the short tail shaft as the angle of the drive shaft will be too steep with a long tail shaft.
Tim

 

I have to disagree with Tim; you're talking about a difference in length of about 6 inches in the tail shaft. With a 5 foot driveshaft, the difference in angle is minimal.

I am assuming you have the 10" long tail housing, if you have the 18" long housing, you will need to go shorter.

What you might run into is contact with the tunnel or floor braces, as the A-bodies were designed around the short tail shaft transmissions. I have used both the short and long(really: mid length) tailshaft transmissions in A-bodies.

A trial fit might be in order, to see how things fit. Do this before you shell out more cash, it may be worth it.

Jim

 

I was assuming that the driveshaft would have to be shortened even for a short tailshaft 400. Is this correct? or is the short tailshaft 400 the same length as the T350?

Thanks

 

The tailshaft from a 73-77 Grand Prix is what you need. Easy to find at a junkyard.

 

The 400 will be longer than the 350. The output shafts are also different: Spline count and diameter. There is such a thing as a TH-375 that uses the same splines and diameter as the TH-350, but, these are harder to come by.

You will need to shorten the drive shaft and have the different yoke installed for this swap.

Jim

 

All you need is the yoke and tailshaft , like from a 73-77 Grand Prix, (short tailshaft THM400 standard) and bolt it right in. The drive shaft is fine as is...

 

I have a line on a T400 BOP with a 4" tailshaft but I don't know what it is from, would that be the same as the one you are recomending or is there something else special about the Grand Prix one?

 

It may very well be the same. I don't know.

 

I have the dimensions listed on our site.
You will need a d-shaft 54.25" when going with a shortshaft TH400 and
the corporate 8.5" rear found in 71-2 Skylarks.

Also, you will need to get the proper gas pedal set-up with downshift switch. You can get the brkts and switch from www.mrbuick.com

 

When you say 54-1/4", is that center of U-joint to center of other U-joint?

Thanks to everyone for the info. Everyone on this site is very helpful!!

 

Correct, center of u-joint to center of u-joint