55.2-59 Will 17.5 spare tire fit on side mount

[ses427]

Converting to a side mount spare on a 56 SWB and would like to use the original 17.5 inch wheels? Does anyone know if it will fit in the cutout? Thanks.

[mongocanfly]

it would be dictated by the tire size, not the rim size..as long as the bolt pattern matches the mount

[mr48chev]

^^^^^^^ what he said. I can remember seeing some oversize snow tires/mud grips that didn't fit on smaller rims before.

[ses427]

Thanks, I understand the point of tire size. This is a restoration so the only 17.5 inch tires are the STA's. No mondo size tires, guess I could measure from the center of the tire carrier to the cutout to figure it out. Since neither the mount or the fender are mounted yet, thought someone might have run across this during their rebuild.

[dsraven]

I had a 57 3/4 ton with a mondo sized spare and it fit. 8 bolt wheels. don't remember the tire size though.

[_Ogre]

as stated, tire size not rim size would determine spare tire fit in the fender cutout. truk has 28" tires on 15" rims, you could probably fit a 30" tire in there. you'll also need to modify the mount for lug spacing and back space of the rim. i use stock mirrors, i had to modify the drivers mirror out 2" to see past the spare

[57tailgater]

Originally Posted by _Ogre

i use stock mirrors, i had to modify the drivers mirror out 2" to see past the spare

This is why they had the original peep mirrors. To see over the fender mounted spare.

[_Ogre]

i don't believe peep mirrors were ever an option, always an aftermarket add on
i've owned a couple of these trucks with fender mounts
never was an issue until i mounted a wide tire on there

[MJN]

Good thinking- got me wondering about that on mine. I'm putting 19.5's on my Napco. On my '56 3600 from the center of the spare wheel mount to the rear fender is 18". The OD of one of my 19.5" wheel/tires (8-19.5 tire) is roughly 33". I'll have to dig one out and try it out for size yet but should work.

[_Ogre]

if your 3600 truck has the longer step, which puts the tire lower, you probably have a better chance at getting a big tire in there with less cutout

[MJN]

Originally Posted by _Ogre

if your 3600 truck has the longer step, which puts the tire lower, you probably have a better chance at getting a big tire in there with less cutout

Yes, 3/4 ton (3600) had the long bed, so it won't be an issue for me.
For the OP- the GM Vehicle info kit shows 7-17.5's were optional. The wheel/tire had a rolling radius of 14.3", OD of 28.6". That was stock and may differ from what tire you end up running.

[57tailgater]

Originally Posted by _Ogre

i don't believe peep mirrors were ever an option, always an aftermarket add on
i've owned a couple of these trucks with fender mounts
never was an issue until i mounted a wide tire on there

I could be wrong but I do know there is this style for the '55-59's. It doesn't clamp on. The base is contoured to match above the door window and you attach it with 2 bolts with holes drilled through the door - not clamped on like most peep mirrors. I also thought I read somewhere at sometime where the spare tire caused a need for this. May have depended on the size of spare too just as you found out.

[MJN]

Here is the list of accessories from the GM Vehicle Info Packet for 1956 trucks. I don't see a 'peep' style mirror listed but there are some interesting accessories-maybe carry over from cars- like the electric shaver

[_Ogre]

i wish they had prices list for all those options. i knew turn signals were optional, r.h. stop/tail was too

[IamBrian]

My sons 57 GMC 100 NAPCO w side mount and optional 17.5“ wheels has the tire mounted in its original location using 8.00-17.5 tires. We stumbled on these slightly used tires for a great price, and luckily the spare barely fit (I used my hand to tap it into the fender as I tightened the lug nuts) but it rides there.

[G&R's57GMC]

Here is my '57 with a 16" wheel and the tire is 32" diameter still has room for a 33" diameter tire .

Note : the fender is different on the long bed , it allows the tire to mount lower compared to the short bed .

[dsraven]

here is my Canadian '57 GMC 3/4 ton long box. it shows the wheel in place. stock stuff but don't know exactly what tire size it had. long box fender is further behind cab due to longer step, as noted before.