Difference between Distributor Shafts
Thread Starter
Melting Slicks
Joined: Apr 2005
Posts: 3,113
Likes: 4
Difference between Distributor Shafts
How does one tell the difference between different distributor shafts-high performance, standard, and TI shafts, if the TI shaft is any different from one of the others.
Thanks
Thanks
Pro
Joined: Jul 2008
Posts: 622
Likes: 24
From: Clermont Florida
Other than the 1111263 TI ball bearing racing distributor, I believe all tach drive Corvette shafts will interchange. There are however, some differences.
Some of the high performance shafts have oiling grooves where the upper bushing rides.
Both TI and point distributors use the standard shaft
The main difference is the TEE piece that is braized to the top of the shaft. The shape of this Tee varies from high to low perf, and governs the advance curve, bringing it in sooner or later, according to the shape. Different springs also affect the curve. A bushing on the underside of the Tee limits the number of degrees of advance.
I was told by a Corvette TI rebuilder that there were 23 different shafts originally available, each with a different Tee. There is a 3 digit number stamped on the Tee, which is why you will sometimes see a listing on the "Bay" noting correct (number) shaft.
Today, I only see 2 different shafts available. High or low performance. You could switch your original Tee to another shaft, but indexing it to the oil pump tang is CRITICAL, as this affects distributor positioning for correct timing, and Corvettes have very little room for adjusting the distributor.
Rich
Some of the high performance shafts have oiling grooves where the upper bushing rides.
Both TI and point distributors use the standard shaft
The main difference is the TEE piece that is braized to the top of the shaft. The shape of this Tee varies from high to low perf, and governs the advance curve, bringing it in sooner or later, according to the shape. Different springs also affect the curve. A bushing on the underside of the Tee limits the number of degrees of advance.
I was told by a Corvette TI rebuilder that there were 23 different shafts originally available, each with a different Tee. There is a 3 digit number stamped on the Tee, which is why you will sometimes see a listing on the "Bay" noting correct (number) shaft.
Today, I only see 2 different shafts available. High or low performance. You could switch your original Tee to another shaft, but indexing it to the oil pump tang is CRITICAL, as this affects distributor positioning for correct timing, and Corvettes have very little room for adjusting the distributor.
Rich
Last edited by landshark 454; May 1, 2009 at 02:27 AM.
Thread Starter
Melting Slicks
Joined: Apr 2005
Posts: 3,113
Likes: 4
Thanks! The one i currently have has an S or a 6 followed by a 5. I was told that it is the incorrect shaft, but i have no way to verify that information. Can anybody help? This is 66 427/390 TI distributor.
