Specifications

The new Rear and Brakes!

I didn't get all the pictures I should have... But here it is in place. I had the axle cleaned up, and the new hardware put on at Jantz Engineering over in Poulsbo.

This is what it looked like with a new wheel cylinder in place.

And with the new shoes and hardware back in place.

And here we are taking a photo op during the test drive. This is actually in the Target parking lot in Silverdale. We drove to Silverdale because the highway between here and there is the nearest one that has mile markers, and we wanted to check the speedometer against the clock to see how close it is with the new gears.

I should explain first, that it was wrong before. This truck came with a 4.11 differential originally. When I got it the rear was 3.54, and the speedometer read about 5 mph slow at 50 mph. That's a subjective measurement, and I never clocked it to get a precise measurement.

With the new 3.08 rear I knew it would be quite a bit off. 4.11 divided by 3.08 is 1.33, so the sub would be traveling about one-third FASTER than indicated on the speedometer. And my fuel economy measurements would be off that much too. That just didn't seem acceptable.

As Stu and I removed the engine and transmission from the donor car, I had noticed that it had a Stewart Warner ratio adapter installed. That surprised me a little, but it also reminded me that the 1970 Blazer I owned 20 years ago had a similar device on it. I knew about that adapter because the second time I replaced the transfer case on the Blazer I never got around to reinstalling the ratio adapter.

It took a little digging, but once again I've proven the value of keeping junk like that on hand for 20 years or more. The old ratio adapter from the Blazer is stamped 1.30 in the same place where the one I removed from the Chevelle is marked .9743. I put the Blazer ratio adapter in place, and as tested running down the road, the sub's speedo reads 51 when we're doing 55. Less than ten percent error, and close enough to keep me near the correct speed.

I think the real solution is to spend some time taking careful measurements, and calculate exactly what the ratio should be, and then get a new ratio adapter that is exact, but don't hold your breath, other projects will come first.

Last updated: December 31, 2006