Re: Rear gears
 

Because it's cool to have a factory dash tach in a truck. Who really needs a tach anyway? The highest performance vehicle I have is my Harley and that has no tach. I listen to the motor. Most trucks have automatics that shift themselves.I've always put tachs in what I drive because it says performance,like cool wheels and tires or dual exhaust. Extra gauges in cars from the '60s and early '70s set them off. Same with trucks.

Re: Rear gears
 

I've got the same HO52 diff in my '69 C-20..I always thought the ratio was a 4:56, but I suppose if it's actually a 4:57 I wasn't far off..Anyway, my engine spun @ 3000 rpm when doing 55 mph, but since yanking the 3 spd saginaw out and replacing with a 4 spd OD, the rpm is down to 2200 @ 55 mph...Don't know if this helps you at all, but I much prefer being able to hear myself talk when trying to have a conversation with a passenger.

Re: Rear gears
 

Always nice when not having to change out the rear end. Any specifics on the year and model of this 4 spd OD, and modifications necessary?

Re: Rear gears
 

Its the cool factor of having that center hole filled with something.:lol:

Re: Rear gears
 

Factorystock,Sorry I lost track of this thread...my kids were on the computer and I forgot to go back to it. The tranny I swapped for the 3 spd is a New Process GM MY6...They were used in Chevy trucks from early to mid 80s I believe.My goal was to improve my gas mileage a bit w/o having to change rear end gears.while it did get the revs down some, I still only get 10-11 mpg.

http://i234.photobucket.com/albums/e...kman/005_5.jpg