Project Nomad: 1986 GMC Jimmy Sierra Classic

Darkrider

Adventurer
For the front brakes.................. Pure Chevy Sex

The rear, yep larger 8.6 axle. Any 10 bolt spring axle is an easy job. The 99 up new style Silverado alxe is perfect for square bodies. The rims in my pics are close to zero offset. I've lost a couple pics in the photobucket crap, but have replaced most of them in the link. If you read the whole thread, I also cover the rear axle swap. No changes were required for the master cylinder, stocks works fine. And it is proportioned exactly for my burb, should be fine on a blazer, but a pick up might need to add an adjuster to the rear lines.

For the front, only things needed "custom" are cutting down the hub into a rotor over hub arangement, the brackets, and drilling hub and rotor for what ever lugs you decided on. I went 14x1.5 to match the new rear axle.

Will def give your thread a read through. Though it seems Thorparts does not list the caliper brackets on their site so that is worrysome. However there are brake upgrade options in the form of the Wilwood dual piston calipers. so there is that. Plus with the Wilwoods i can keep my 15" wheels. From what i understood of your thread thus far 15"s will not work on the disk brake rear but possibly on the drum brake version?
 

chilliwak

Expedition Leader
It will be very interesting to see what you do with those axels and big block Cadilac motor. Start saving some funds now for your build. I think you could have a lot of fun with those sweet GM rigs. Cheers, Chilli..:cool:
 

cyclic

Adventurer
You have to call or email to get the brackets. You can fit 16" rims depending on the rim itself, but 15's will never happen, even with drums. The reason for the braking improvement is the larger brake surface. The Wilwood stuff works better than the stock 1950 brake design, but doesn't come anywhere close to what the larger rotor and four piston brakes give you. Outside of a new truck, I've never had a vehicle (let alone) a suburban stop so fast and solidly. Another huge advantage to the H3 system is the hat over hub arrangement. Everything about servicing the front is easier, brake jobs are stupid easy. The rotor now fits over the hub like a modern vehicle. The pads can be accessed with only taking off the wheel. The caliper is a fixed design, so no more stuck sliders/calipers. No lubing/lube near the brake surface. Front bearings are a dream to swap or adjust. Brake work no longer involves pulling hubs. I went 17 over the 16 because of tire selection. I actually run 265/70R17 tires. A very common size for new/stock vehicles. 32" is perfect for my set up, but the selection of 17" tires is amazing.
 

Darkrider

Adventurer
It will be very interesting to see what you do with those axels and big block Cadilac motor. Start saving some funds now for your build. I think you could have a lot of fun with those sweet GM rigs. Cheers, Chilli..:cool:

Well the early square is a no go as it is a parts truck for one of those "i'll fix it someday" type of builds.. However the early K5 may still be viable. If that is the case i will probably look at dropping the 500 into it with the 8 lug axles.

You have to call or email to get the brackets. You can fit 16" rims depending on the rim itself, but 15's will never happen, even with drums. The reason for the braking improvement is the larger brake surface. The Wilwood stuff works better than the stock 1950 brake design, but doesn't come anywhere close to what the larger rotor and four piston brakes give you. Outside of a new truck, I've never had a vehicle (let alone) a suburban stop so fast and solidly. Another huge advantage to the H3 system is the hat over hub arrangement. Everything about servicing the front is easier, brake jobs are stupid easy. The rotor now fits over the hub like a modern vehicle. The pads can be accessed with only taking off the wheel. The caliper is a fixed design, so no more stuck sliders/calipers. No lubing/lube near the brake surface. Front bearings are a dream to swap or adjust. Brake work no longer involves pulling hubs. I went 17 over the 16 because of tire selection. I actually run 265/70R17 tires. A very common size for new/stock vehicles. 32" is perfect for my set up, but the selection of 17" tires is amazing.

Ahh ok will def look into it then. It looks like i will be getting the rear axle from the 800 i meantioned. It is an '01 and i suspect more then likely geared with 3.42s and the same G80 that is in the original axle. Plus i can get the wheels off of the same '01 Silverado. Now my question is is the center bore of the stock steel wheels from the Silverado large enough to go over my hub? If so that solves my wheel problem as does the fact that the friend that has those parts also has some 245/70R16 tires as well as some 215/85R16 tires. The 215s would be a damn near match to the current 31x10.5R15s on the truck now. Still going to pick up the 245s from him as well for another project of mine. May end up saving the 31s from this for a bush buggy project i will possibly be starting soon. If the Silverado wheels will not work, well i will probably still grab them as i will be using the original 10 bolt from this truck to convert my '84 Chevy C10 to a 6 lug truck.
 

cyclic

Adventurer
The center hole on the H3 front is the same as the square body. But the silverado rim center holes are too small, and the offset is not ideal. Read the thread, covers a bunch of the info. The center hole on the Silverado rims can actually be opened up with a regular router. There are some youtube vids showing how. But I would look for some different rims, as something close to a zero offset is ideal. The stock rims run at least an inch of negative offset, which will pull the tires way in on the front end. But would be okish on the new rear axle since it's a total of 4 inches wider (2 per side).
 

Darkrider

Adventurer
The center hole on the H3 front is the same as the square body. But the silverado rim center holes are too small, and the offset is not ideal. Read the thread, covers a bunch of the info. The center hole on the Silverado rims can actually be opened up with a regular router. There are some youtube vids showing how. But I would look for some different rims, as something close to a zero offset is ideal. The stock rims run at least an inch of negative offset, which will pull the tires way in on the front end. But would be okish on the new rear axle since it's a total of 4 inches wider (2 per side).

Fair enough, So H3 rims or aftermarket wheels with 0 offset it is! Upside is that i can still make use of those silverado wheels on some other project.
 

Darkrider

Adventurer
Pretty cool dark rider. We both have pats and full sized chevys

That is pretty cool indeed. One thing i keep kicking around with this is converting this one into a Half Cab especially if i get the '69 K5 i have a lead on. But one other likely outcome is keeping this one as is in terms of being a full cap like it is now. May seriously look at the idea of those 8 lug axles under the '69 as that will make it easier to convert it to disk front brakes and gain a pretty heavy duty rig. I still want to do a Half cab at some stage so who knows what may happen. This past week i seen a bumper design on a buddies Lexus that i may just end up copying for the rear and design one to go to the front that is of similar design.
 

Darkrider

Adventurer
Slight shift in plans with this truck mostly due to other plans changing. It looks like getting the '69 K5 is not feasible due to cost of getting it here. Plus further going over of this one revealed that it would be a good candidate for mild restoration. So the goal now is to get rid of the rotten metal and covering the repaired areas with color matched bed liner. Fitting nerf bar style steps in place of the running boards that caused the rot in the first place. Still more then likely going with dual baja style exhaust exiting just ahead of the rear wheels. Working on a few different ideas for bumper designs currently.
 

1stDeuce

Explorer
If you are still open to rear axle upgrades that don't lead to much reduced clearance and 8 lug hub conversion on the front, there is a 9.5" 14 bolt semi-floater that came with 6 lug hubs on many 90's "light duty 2500" trucks. (Basically a half ton with a heavier rear axle...)
It is still a c-clip axle, but comparable in strength to a Dana 60. I think at that point, you're not going to be able to break it, so who cares... Should be able to find one with 4.10 ratio and a G80 with a little looking. Upgrade the front 10 bolt to 4.10 and you're good to go.

IIRC, the 2wd version of the 14 bolt semi floater was close in width to the front 10 bolt... The 4wd version was wider than the front axle by a few inches...

If you go the 8-lug route, the same 14 bolt semi-floater is a good option still, and offers almost 1.5" more clearance than the 14FF IIRC. As I think you know, your front 10 bolt can be converted to 8 lug by just swapping knuckles out with an 8-lug version of the 10 bolt, but most 15" wheels will no longer fit. No big issue, since 15" 8-lug wheels are getting scarce anyway. Just go to 16's and you'll have cheaper tires that are more readily available. :)

Man I want to build an old square body chevy again... :)
 
Last edited:

Darkrider

Adventurer
If you are still open to rear axle upgrades that don't lead to much reduced clearance and 8 lug hub conversion on the front, there is a 9.5" 14 bolt semi-floater that came with 6 lug hubs on many 90's "light duty 2500" trucks. (Basically a half ton with a heavier rear axle...)
It is still a c-clip axle, but comparable in strength to a Dana 60. I think at that point, you're not going to be able to break it, so who cares... Should be able to find one with 4.10 ratio and a G80 with a little looking. Upgrade the front 10 bolt to 4.10 and you're good to go.

IIRC, the 2wd version of the 14 bolt semi floater was close in width to the front 10 bolt... The 4wd version was wider than the front axle by a few inches...

If you go the 8-lug route, the same 14 bolt semi-floater is a good option still, and offers almost 1.5" more clearance than the 14FF IIRC. As I think you know, your front 10 bolt can be converted to 8 lug by just swapping knuckles out with an 8-lug version of the 10 bolt, but most 15" wheels will no longer fit. No big issue, since 15" 8-lug wheels are getting scarce anyway. Just go to 16's and you'll have cheaper tires that are more readily available. :)

Man I want to build an old square body chevy again... :)


Oh i am well aware of the 14b SF from having a 1994 Gmc Sierra K1500 Diesel with the F44 package. The F44 was that LD2500/1500HD packaging. Totally forgot about those in the scheme of things. Bonus points for the fact that if i went the route of a 4x4 version of it i can retain my current wheels. Thanks for reminding me about that option! Most of the 4x4 versions i have seen are usually 3:73 with the G80. The 4x4 was wider then the 2wd by 3" (1.5" per side). So more or less with the 10 b front and 14 bsf rear i essentially have a combo that would be comparable to a D44 front and D60 rear.
 

Forum statistics

Threads
185,533
Messages
2,875,612
Members
224,922
Latest member
Randy Towles
Top