flattie,
I have been looking at the idea of going to a winters quick change.... I am told that the "V8" style Winters QC is more than up to the task of handling the power i am putting to the ground at Bonneville....But for a new cost of $3000 and probably more, I am having a hard time getting myself interested in spending that.
One of the problems I am facing with the lakester is that it has pretty well got to maximum power at the 3 1/2 mile mark.... it was good for the record, mind you.... but it only picked up 5 mph from the middle mile to the last mile. I think I could easily use 2 to 3 precent more gearing. The best I can do with a Ford 9" is a 10% jump (from the present 2.75 to 1 up to 2.50 to 1) . The car may surprise me and pull the ratio but, having raced at Bonneville all these years has taught me a few things..... one of those things is that 10% in the rear end ratio is to Bonneville racing as what a light year is to astronomers- a large increment! So,the Olds rear end keeps coming back as a possible choice due to the availability of 2.69 to 1 and 2.56 to 1 gearing.
Another problem is that we have another lakester that is in the works and well along. It is more of a "laydown" seating position and probably a little more aerodynamic than the present car. It has a "champ" quick-change in it. Our plan was to use the present lakester as a test bed for a running gear combination and then transfer the running gear and knowledge acquired to the new car. I expect that the new car will run in 2012. So, I have very little interest in doing any massive rebuilding to the present lakester in order to accomodate a different design rear axle.....
The rebuilding that would need to be done would include, of course, building a new differential and axle assembly and possibly changing the engine/transmssion height in the car by the pinion offset differences between the Ford 9" and whatever other rear axle that is selected to replace the 9". However, I figure that the 3/4" difference between the Ford and the GM axles would be an amount that I can live with as the rear of the car is presently a slight bit lower (about 3/8") than the front end (a design error when building/installing a new front axle 2 years ago - and, as usual, it is a long story).... the 3/4" difference would raise the rear of the car to be about 3/8" higher than the front of the car.... with 218" wheelbase and 24 degrees of caster (with the car at level), it looks like the caster angle change would be way less than one degree - perhaps not even a measureable amount of change..... but to do it all and to use the car for only one more season .... I'm just having a hard time getting excited about doing it.
Thus the desire to know the pinion offset dimension for the Olds rear end....