New Rear Tires?

I'm studying getting new shoes for the 300 before spring fieldwork sets in. She's got 13.6-38's on now, but I've found a set of NOS 12.4's locally for a decent price. Any reason to avoid them? Will I notice any difference in performance? Any and all information and opinions are appreciated.

Mac

No issue, do it. Jim

12.4's are the "old" 11-38 size, 13.6's
are the "old" 12-38 size. These "old"
sizes were the sizes that were used when
your 300 rolled off the assembly line.
Your 300 probably came off the line with
11-38's. If you had 13.6's on it, you'll
probably be disappointed with 12.4's.
(Just my $0.02 worth.)

They will be fine

Go for it. You will not be disappointed. I have a pair of 12.4 x 36 on one Farmall 340 and a pair of 13.6 x 36 on another Farmall 340. There does not seem to
be that much difference to me.

Thanks guys! Sounds like they may be the way to go.

Mac

Years ago we went the other direction to 14's on our MD glad we did.

I have 12.4 x 38 on my Super H and they are great. 300 is basically the same tractor.

The switch from 11-38 to 12.4x38 and 12-38 to 13.6x38 actually took place in 1954. Our January '54 built
Super H still had the factory installed Firestone 11-38 6 ply 45 degree lug tires when we got it May of
'68. Big dose of road work caused them to get replaced in '69 with Dayton 23 degree 12.4x38's that are
still on it at about 75% tread yet, they wear like iron! The factory Firestones were used on a set of
clamp-on duals Dad made for it. Talk about flotation and ZERO slippage! We planted corn with it, peg-
tooth harrowed ground, light tillage.
Typically M's had 12-38's which changed to 13.6x38's. 400's can have either 13.6x38's or 14.9x38's, the
old 13-38. Most 450's I've seen have been on 15.5x38's. And most 350's on 13.6x38's.

IF the deal on the 12.4x38's is good enough, go for it. I hope they're 6 ply. Depending on what your
doing with the tractor will determine how happy you will be with them. For stuff like haying, road work,
will be no change, just a very slight decrease in actual ground speed. Tractor will seem to have more
power, slight increase in slippage under hard drawbar pulls.
I could have got a great deal on brand new Firestone SAT-2's in 15.5x38 two years ago for my M. But
by the time I bought the correct DW14-38 rim, or had my 12 in rims widened to 14 inch it was going to
cost WAY more than the proper 13.6x38's would have cost.
I have seen a couple Farmall 300's at tractor shows on 12.4x38 rear tires.

I had to Google NOS to figure out the hard
way it means new old stock. All I can
suggest is 6 ply is way better than 4 ply,
and Google the brand to make sure there not
junk.

(quoted from post at 14:29:19 03/06/20) 12.4's are the "old" 11-38 size, 13.6's
are the "old" 12-38 size. These "old"
sizes were the sizes that were used when
your 300 rolled off the assembly line.
Your 300 probably came off the line with
11-38's. If you had 13.6's on it, you'll
probably be disappointed with 12.4's.
(Just my $0.02 worth.)

Click to expand...

exactly what he said! according to Nebraska test the 300 had 11x 38 tires on it but I wouldn't put them on mine regardless of the "deal"
I have 13.6s on mine and would not put anything less on it