Vortec head swap potential

[Erik the Awful]

You need some numbers and a bit of math.
What size rear tires? You can always switch to a shorter tire to get a better ratio.
I believe your 4th gear ratio is 0.696.
Plug in your desired ring and pinion ratio.

Calculate RPM for Given Speed(MPH), Rear Gear Ratio, and Trans Gear Ratio

Calculate RPM for Given Speed(MPH), Rear Gear Ratio, and Trans Gear Ratio

purperformance.com

 

[Diego916]

You need some numbers and a bit of math.
What size rear tires? You can always switch to a shorter tire to get a better ratio.
I believe your 4th gear ratio is 0.696.
Plug in your desired ring and pinion ratio.

Calculate RPM for Given Speed(MPH), Rear Gear Ratio, and Trans Gear Ratio

Calculate RPM for Given Speed(MPH), Rear Gear Ratio, and Trans Gear Ratio

purperformance.com

The trans gear ratio on the calculator the same as 0.696 for 4th gear?

 

[Erik the Awful]

Yes, that's your highest transmission ratio, and you'll be in that gear on the highway at 70 mph.