About the wheel thing mentioned earlier on in the thread.
If you think that changing to 19.5" rims will make you go faster than keeping your 20" rims think again.
The tallest tire you can get in 19.5" is 8X19.5, and they are about 31" to 33" tall.
The 8.25X20 tire is close to 38" tall.
The taller the tire the faster you go.
If you want modern wheels the dirrect replacement for a 8.25X20 tire is a 9R22.5.
However, I have yet to find a 22.5" rim with our small 10 lug pattern.

I am currently running 8R19.5 and am thinking about modifying some wheels so I can run the 9R22.5.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-