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Will they fit?

I think it will come down to back spacing with 14in width. gama goats 1100/18s (41') fit but are spaced out with the center of the tire at the lip of the fender. 44x18.5 will fit but turning is the rub.

Thanks for the photos.

I wish a 12/42x16 directional Irok were available. 14 is wider than I actually want. I don't mind the tires sticking out past the fenders, but I don't really want more than about a 42 diameter. I have a big block Chevy in this truck with stock axles and 5.83 differentials. I think that combined with really big tires would be a real axle-breaker.

What do you have to do to the gamma goat centers to fit them on a 37 ?

42's are cool, no doubt about it. But, if it makes the truck mostly unsteerable, then why bother? I'm reasonably sure you could accomplish the same look, feel, and attitude with the 39.5x13.50/16 Irok and still be able to enjoy driving the truck. Either size of tire will be an axle breaker though given the BBC under the hood; heck, the 230 would break axles with that much tire too...

Why do they make the truck mostly unsteerable, more so than the 39.5's?

I put the BBC in it more than 40 years ago. Truth to tell, it hasn't been all that bad about breaking axles since then. You just have to apply the throttle appropriately.

JimC wrote:Thanks for the photos.

What do you have to do to the gamma goat centers to fit them on a 37 ?

goats don't have centers (their kinda like a dayton) they need to be made from a piece of plate. here is a pic of my buddy's truck with goats



I don't think the 42s will be much of an issue with the right offset they may rub on the rear fender and box but even a 900/16 will rub on the box @ full articulation. if I was running a < 42in tire I would be looking at a shackle lift for the front and a shackle flip in the back to keep clearance for snow chains. then before i took the truck out on the road I would be upgrading the brakes with disks and/or a booster failing that i would weld some steel to the brake peddle so I could use both feet
44/18.5r15s at full lock

I think the boys in blue would want a mud flaps if they stick out like this

Thanks for the photos.

What's snow? (I'm from pretty far south)

"Unsteerable" might be too harsh a term. The real question is how much rubbing do you want to put up with? And the real manly question is do you have power steering swapped in? A few 3-4 point turns in the parking lot, or on the trail will make it very clear what the next upgrade should be. The 39's would give you about an 1.5" of additional clearance between the tire and the lower fender mount when your turning the tires left or right. This might reduce or eliminate the rubbing you'd find with the 42's...

Plus, with the stock rims being only 7" wide or so, you'll find the 42's will wear poorly on the center tread due to the sidewalls being pulled in so far, unless you want to run them at about 15psi to get the tread to wear evenly.

IMHO it would be better to re-center a set of 2pc H1 hummer wheels and gain the addition of a bead lock than to try and find some obscure Gama Goat wheels to carve up. The aftermarket has a lot of wheel centers to choose from to accomplish this and they are still a mil-spec wheel, so it should look fine on the M37...

Here are a few shots of mine as I tried to figure out the best way to mount the 44x18.50/16.5's

Here is the 44 in the fender well, not mounted on a wheel, but the center of the tread is placed in the same spot as the center of the factory rim.


With recenterd wheels:


still lots of room inside:


This was measured out while planning for my D60 swap, and using the H1 wheels in the oem configuration.


I finally ended up with the D60, stock 7" steel wheels, and 1100/16's


The biggest hurdle to big rubber, is the lower fender support. The tires will fit just fine if you only travel in a straight line.

Yota, H1 rims look nice. What tread pattern is that? I like it. Reminds me a bit of the old Firestone Super All Tractions I used to run.

Master Yota wrote:"Unsteerable" might be too harsh a term. The real question is how much rubbing do you want to put up with? And the real manly question is do you have power steering swapped in? A few 3-4 point turns in the parking lot, or on the trail will make it very clear what the next upgrade should be

with the crazy offset on my custom 15x15in rim I found it easier to steer the 44x18.5s verses a set of 38x13.5s I had mounted

unsteerable is not too harsh a term with a stock worm and peg box, 900/16s ndts and 5 or 6 point turns needed on coastal trails

JimC wrote:Yota, H1 rims look nice. What tread pattern is that? I like it. Reminds me a bit of the old Firestone Super All Tractions I used to run.

The 44's are called Ground Hogs, and they are still available in many sizes, some even in a radial. They used to be made by Denman, but since Denman went under a few years ago, I don't know who is making them anymore. As for my 1100/16, they are a Michelin X series of radial tire. I've never seen another set with that tread pattern though, and they are not re-treads.

Many thanks to both you guys. I've owned my XM708 for over 40 years and have left it stock. I've had my 37 for 51 years and it isn't (but my memory of what I did to it half a century ago is sometimes somewhat vague). I had four engines in it back in the 60's, the 230, a slant six, a 318, and the BBC that I put in it around 1970. From memory, my intended power steering box was out of a 69 Pontiac Grand Prix, but it rotated in the wrong direction, so I used another GM power steering box of identical appearance but opposite rotation. Upper steering arm was clipped to fit. Steering has been back to stock for a long time now, courtesy of one of my parts 37's, but returning to the GM system would be a bolt in. This truck was my daily driver back in the 60's, so saw a lot of highway use then, but overall, its been almost entirely an off-road truck. There's no rock or snow around here, just two types of mud, one modified loessal, the other gumbo, and I've always had better performance in both from tall, skinny tires that cut down to the hardpan rather than float on top. I like bias tires, and I like the Super All Traction pattern mostly for sentimental reasons (they were a gift from my foster brother, as was the truck itself). I doubt this truck will ever see a highway again, but hopefully it will wallow in a lot more mud in years to come.

It is starting to look like my my cheapest route might be to cut down the centers from some of my excess 37 rims and mount them in wider either 16 or 16.5 tubeless rims to keep a semblance of the original look and allow control over the backspace. I think I'd continue to run tubes and flaps though.

Jim, you may have good luck with a company called Stazworks - http://www.stazworks.com/ - as they can do just about anything with an H1 rim, and if memory serves have already built several sets of converted wheels with the M37 bolt pattern. They also offer a different bead lock insert for the H1 wheels that retains the function, but gets rid of the pia run-flat assembly.

Another option would be a different tire; some folks poo-poo the Super Swamper line of tires, but for an off road truck that see's mostly mud, they are tops. I would maybe consider a TSl Bogger in the 38.5x1100/16 size. You wouldn't have to change anything at all to run them, provided you have hard pan under your mud as they will dig like crazy.

Master Yota, I have a dumb question, what's the red and spring doohickie sitting where the bumpstop usually goes?

MM

I've thought about the TSL boggers. They are great tires, but 38.5 isn't really tall enough to cut down to our average hardpan depth.