Guys. A couple of points here.
First, Steve70, if your angle does not look like the diagram.....Yes indeed the vibration is coming from mismatched angles. The center line of the crankshaft and transmission output shaft must be parallel to the center line of the pinion shaft as shown in the figure above. There are NO exceptions to this configuration unless you are a serious drag racer.
Camaronotcamaro....wrap up doesn't always happen if corrected for. And, you set the driveline for the most common mode of operation...cruising which the pinion is basically in a static mode. After initial wrap up deflection, the angle starts to decrease proportionately. If you are using the car just for drags then angles should be studied further for optimization and hopefully traction bars in place if you are worried about wrap up. Four bar links do not move at all. So, no need there.
68ssconvertible.....you are wisdomic in your post with one exception. "I think the tranny pointing up is more common, but sometimes it points down"
This statement is incorrect. Most,if not ALL engine driveline designs are pointing the tranny down at the rear. There are several reasons for this. One is that it gives gravity a chance to work with the lubricant return mechanisims and cooling passages to natually expel air. All longitudinal mounted engines that I know of drain oil to the pan visa via gravity with oil flowing back and cooling systems (water jackets in the blocks and heads) to expell air with a planned downward plane in back. Also, note that most intake manifolds have built in corrective leveling angles of 3 to 4 degrees to allow the leveling of the carb. Some modern engines have as little as 2 degrees down in back.
GDV350SS....you are absolutely correct. Stock positoning of the Camaro should be found at 4 degrees down in back. Of course modifications that many throw in could alter this, but I have always found 3 to 4 degees down in back. This was the GM specification as well for all V8s longitudinally mounted to date except fuel injection cars which is 3 degrees. Your vibration is coming from mismatched angles for sure, I would bet on it.
Hope this helps!
ConceptOne Pulleys and Brackets
Northern/Southern Rodder Magazine's "Jack'Stands" author and creator
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[This message has been edited by HOTRODSRJ (edited 08-16-2002).]