The Stovebolt Site Forums The Shop Area The HiPo Shop Tire size on 1946 Chevy truck

Hello,

I have a 350 Vortec with a 700R4 with straight front axle in a 1946 chevy 1/2 ton and rearend out of a 1953 or newer truck. I plan to run 235/75R15's on the rear on 8 inch aftermarket rims. I am debating about running a 205/75R15 or 215/75R15 on the front. I am using the old steering box that has been rebuilt. No power steering. To save discussion, I am not worried about interference with these but would like to know anyone else's experience with steerability and handling with a wider tire than original. I believe original was a 7 inch tire and around 28 inches tall. I would like to go with the 215 but don't want to sacrifice too much steerability just for a wider tire. Suspension is factory except for 3 leaf springs removed from front and rear.

To follow up, I am leaning towards the 215/75R15 due to the fact that there is a limited selection of wheels in the 6 inch width. I am looking more towards a modular type wheel. Any opinions on chrome wheels? I like the looks but have read/heard some general feedback about the chroming process as good as when I had modular wheels on my Mustang 30 years ago and rusting prematurely. Any thoughts?

Regarding the tires your truck was originally fitted with, I am pretty certain that they were not 7 inches wide. The '48-'52 shop manual shows 6x16 tires as standard for a 3100 pickup. Those tires would have been closer to 30" or 31" in diameter, not 28".

Short, fat tires on 80 year old trucks without power steering make driving a miserable chore. The taller and skinnier the tire, the easier and more pleasant the truck will be to drive. Larger diameter tires also make it possible to drive at highway speeds at lower engine rpm.

Ol' Roy came to me with 15"x8" rims. It was IMPOSSIBLE to steer at low speeds and very hard to steer at higher speeds.

I replaced the horrible 15" rims with 16x6 wheels from Wheelsmith. Those wheels and tires coupled with new shock absorbers made the truck as easy to drive as any other vehicle I own.

These rims allow the installation of 225/85R16 tires which are closest to the outside diameter of the original tires.

Hilarious - Here are some snapshots of the stock tire and wheel data details from the 1946 Chevrolet Truck Data PDF at the GM Heritage site.

Are you planning to run stock 15" rims or another wheel? The RPO optioned 15" rims are listed as 5.50" wide and the tire details indicate that a stock 15" tire used a 7" tube, which is probably where the 7" wide tire measurement comes from. A little web searching indicate the recommended minimum rim width for the 215 tire is 5.50", so you should be okay with the original RPO wheels if that is what you have.

The difference in width between the 205 and 215 tire is only a little under 5%, so not much difference and may not be a significant change to your steering effort level.

The taller, skinnier tires (16x6) do make steering a bit easier, but the call is yours based on what you want for steering effort coupled with other factors (appearance, stance, etc.).

I'm interested in seeing the result of your choice.

EDIT - I missed your mention about getting some modular wheels. 6" width will suffice for the 215 tire for safety standards. From there it all about appearance choices I think.

I have 205/75R15 radials on 4" or 5" rim, I need to look to be sure what size they are, aired up to 32 psi on my '37. The rears are 235/75R15 on a 7" rim. Mine drives very easy with a 1941 steering gear box ( same as your '42-'46 ) gear box. I've had this size tire combination for 26 years with no issues. I have a 250 inline six / T350 automatic with straight axle, so its lighter weight than a stock 215 would be and lighter than your 350 and 700R4. A 205 might be a little lite for your weight, so look at each tire size carefully.

Thanks Otto for correcting me. I went by the tire on the old split rims it came with which was a 7.00x15.0. I also wanted to get the stance lowered a bit from factory without aggressively changing the suspension.

I was looking at aluminum wheels but offerings from American Racing, Vision, Ultra etc. don't offer a 6 inch wheel. Going for the chrome or polished look.

Big O tire and online recommended a 7 inch rim for the front if running a 215 and 8 inch wheel for the back. Plan on running a 235/75R15 or 235/70R15 on the back based on my gear ratio. I will go back and look at steel wheels and check my options regarding 16x6 inch rims. I appreciate you sharing your knowledge!