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BIGV6 April 1st, 2017 02:44 PM

Lowering a gmc 4000
 
1 Attachment(s)
Greetings all,
A newbie here. Just bought a 66 GMC 4000.

Would like to drop it about 5". I see spindle kits for 1/2 & 3/4 ton but not for a 4000. Any ideas?

Also, it has 5 bolt 20" wheels. Any idea of what smaller wheels. say 17 1/2", that will fit.

I believe the bolt pattern is 5 X 8 1/4/

POWERSTROKE April 2nd, 2017 08:33 PM

Re: Lowering a gmc 4000
 
That red with a white cab was a really popular color scheme. I have a picture of a brand new '64 C-60 Chevy with 327 truck engine & 4+2 trans with a 20 ft livestock rack on it! That truck had cast Dayton wheels. Guy my Dad drove for brought it out to our farm for Dad to weld up a hitch to pull a loading chute. I road with the owner when it was just a cab& chassis about 100-120 miles from the selling dealer home. Talk about a rough ride! Hit much of a bump or pothole and there would be a foot of daylight under the rear wheels.

I assume you want to lower both ends of your truck, frt & back. I would find a local spring shop in the yellow pages of the largest local town's yellow pages and talk to them about reverse arched springs. Or they may know of spring mounts that can lower your truck. Five inches isn't that much on a medium duty truck. Look for automotive springs, truck repair, or truck body shops.

A smaller tire like a 17-1/2" rim diameter would help lower it more, but I think a 19-1/2" would be all the smaller you could go due to brake drum diameter. There was some method to the madness of the 5, and 6 bolt wheels on the Budd wheels, at least on IH trucks. Seems different weight rated axles got 5 or 6 bolt wheels. Now days everything gets 8 bolt wheels till it's big enough to get ten bolt wheels! Any smaller wheel than your 20" rim diameter with your truck's bolt pattern would be a real "Special". I always hated that word " special", it translates into expensive

Looks like your floor of your box needs some work. It doesn't cast much of a shadow.

Just because I'm nosey, why do you want to lower this truck? I was looking to up-size my F-250 into an IH low profile 4200 or 4300, my local dealer got two in for a local lawn service company, they were too tall for my 7-1/2 ft tall shop door. Killed that idea quick! I wanted a DT-466 powered truck, at least a 7-speed trans, wet kit, onboard air, big receiver hitch, and a 5th wheel, and maybe a hoist under the 9-10 ft bed.

BIGV6 April 3rd, 2017 01:55 PM

Re: Lowering a gmc 4000
 
Thanks POWERSTROKE for the reply.

There is limited distance between the front axle and the oil pan (about 4"). But will try to take out a few leaf springs to gain there.
Good point on the wheel vs brake drum size. I'm going to investigate a lower profile 20" tire. Possibly making a drop bracket to lower the brake plate/spindle.

Very observant noticing box floor or lack of. There was a tree growing through it until recently. Obviously this was a farm truck. Unusual to have the chrome/stainless bumper and grill.

Quite interested in the V6 story. I'm told it was popular for mounting a corn sheller on because of the low end torque. Also told it used as much fuel at idle as running at 60 MPH.

POWERSTROKE April 7th, 2017 05:28 PM

Re: Lowering a gmc 4000
 
Wow, I'm surprised there's so little clearance between the frt axle and oil pan. The C65's I drove with 366 big blocks had 10 inches. There was a couple others, a 350 truck engine and a 292 but I never spent any time under them. Trucks all had 12,000# axles. There was a little C-50, a '67 to '72 vintage that I drove quite a bit, it felt overloaded with 4000# in it. Straight 4speed, was a 350 but it was over-reved and blew up, guy used up ALL the 305's around trying to keep it on the road. Guys would wind it up to 60-65 and it would last 500 to 1000 miles. Owner even blew one engine! I bet I put 5000 miles on it just running 50-55 mph. The other truck I drove was a 1900 FleetStar Binder with 478 V-8 and straight 5-speed geared to run 62-65 with a 45 ft trailer. It was a little overkill for 2-3 skids of freight!

Can't really say what the GMC V-6's got for mpg vs other V-8's. The V-6 GMC's I rode with Dad in carried over 125 gallon of gas, longest run was around 350 miles so never had to buy gas on the road. The 478 V-8 Binder got around 3 to 3-1/4 mpg. It had two 50 gallon tanks and my normal run was 175 miles plus some running around town on both ends so 400 miles or more. I bought 60-65 gallon of gas and a quart of oil on both ends. With the early '80's F-700 Ford with Detroit 8.2L Fuel Pincher with a single 40 gallon tank I bought $20 of fuel every night to make sure I got home, Boss gave me $100 every Monday. That 8.2L lived up to it's name, got 7 to 7-1/2 mpg! The first night I got home with the Binder and only had change left from his $100 he almost cried!

Yes, there are lower profile tires that should fit your wheels. A narrower tire would be smaller in diameter too. A good truck tire shop should be able to fix you up. Have to laugh now, company I drove for used up all the cheap 10.00x20 recaps and used tires, and 11.00x22.5's. One morning I hook to a loaded trailer and do my walk around and thump tires, the one side of the trailer had two 9.00x20's mated to 10.00x20's, the 9.00's weren't even touching the ground! The 10.00's were carrying all the weight. They would last 40-50 miles of my 165 mile trip! I had the grumpy tire guy change them, mate the 9.00's together and the 10.00's together. I think that was the day I had TWELVE TIRES put on my tractor & trailer or had them blow before I got to my destination. A personal record!

6066gmcguy April 8th, 2017 04:26 AM

Re: Lowering a gmc 4000
 
To get smaller wheels to fit, you'll have to know what kind of space you'll need for the brake drum, I heard some one of 19.5" to fit but they used a custom adaptor.

I got rid of the 20" wheels on my truck, replaced them with 22.5" one piece wheel off a 1960 Chevy L60.

My Truck is a 3500, the smallest of the big trucks, but they all used that same 5-10 bolt pattern, 5 on front, 10 on the rear. all the wheels should have 10 holes.

6066gmcguy April 8th, 2017 04:35 AM

Re: Lowering a gmc 4000
 
Check out my Journal thread for some more info and photos, most of the photo bucket pic link no longer work which sucks, but the later entrys are still there for now.

"Jolly's Rescue Squad"


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