Hello all, New here and have some questions

[woody72]

I recently bought a 1988 K5 Blazer with a 350 - 4 Speed, 62000 original miles.

The truck is in very good condition with the typical rust in the rear bed area and the drivers door sill due to it sitting outside with leaking glass seals.

I plan on fixing the rusty areas and replacing all the rubber seals as soon as the UPS man arrives.

Here is my question:

Can I replace the original 7/16 wheel studs with modern 14mm studs so I can run newer style wheels intended for modern GM trucks? If so, what stud should I be looking for? or, what can I do to mount the newer rims?

The local tire shop has a set of awesome looking Eagle Alloy rims that were ordered for a newer Chevy truck but the guy never picked them up. I've been offered them for list price minus the guy's initial payment.

Any comments will help me.

Thanks, Woody

[edman87]

Depending on the mount surface, many newer model wheels can be used. The lugnuts are what centers the wheel, so they are the real key. I know of many that run newer factory wheels on older trucks, myself included on the old 91 I used to have. Maybe the wheels only are only listed for a certain year and newer.
BTW, weren't 88 up 1/2 ton lug studs 12mm? I can't remember and have not had a newer 1/2 ton in a few years.

[edman87]

oh yeah, forgot about the front hubs. Many aftermardket wheels have the large opening to fit the hubs. 6 lug is more common now than it used to be, but many are for 2wd. Usually if there is a lug covering center cap, there will be a large opening or if they take the stamped chrome caps it will also be large. You could always have the centers machined out, usually runs $40-50 per. I opened the center on a set of vintage kidney beans for the wife's bronco 1 time with a router and a careful hand.

[krue]

Welcome to the board!

[woody72]

Thanks Edman and Krue for your replies,

I stopped at the local parts store and rummaged through their bins of wheel studs. I was able to find ones for the front since the knurled part of the stud on the the truck are the same as the modern 14mm studs,19/32". I think they are listed as ones that would fit a 2001 Tahoe.

Looks like I may be stuck with the rears though, they appear to be only about1/2", according to their computer. I thought about drilling out the axel and drum large enough to fit the new studs but I am concerned about getting them perfectly centered. I'm going to have to think about this some more.

I will pull off the rear wheels tonight and maybe knock out one of the studs and have a look.

[edman87]

Good luck. It they were free or junkyard wheels, I would say give it a try, buy buying new wheels, I would want to be certain too.

[woody72]

Just wanted to follow-up with everyone on the results.

I was able to successfully upgrade the wheel studs to late model GM 14mm studs. I'm not going into details of how I did it but I wanted to post the tools and parts needed to make this happen.

Wheel Studs:
Front -- 98564
Rear -- 98596
(These are Advance Auto Parts part numbers)

Drill Bits:
1/2"
9/16"
19/32"
5/8"
(Fastenal is a great place to get these drill bits if there is one close to you)

I step drilled each hole from the original 7/16" up to 19/32", that is why I used the 1/2 and 9/16 bits. The final hole size for slipping the studs in was 19/32, this made the hole big enough to slip the shank of the stud through the hole and left enough meat for the knurled part to grip.

The stud I used on the front was a stepped shank type similar to the stock but bigger, for this I used the 5/8" bit to drill out the rotor to allow the studs to slip through the rotor and the 19/32" in the hub itself which is where the knurled portion of the stepped shank actually grips.

The rears where similar except the studs are not stepped. I also use the 5/8" bit to drill out the brake hubs so they would slip over the new studs.

I am running a set of 16x8 Eagle Alloy Series 1378 (http://www.eaglewheels.com/index.htm)
wheels with 1/4" spacers all around on an unlifted 88' K5 Blazer. The tires are 305/70-16. I had to use the spacers and do a little grinding on the tie rod ends to clear the rims and keep them from rubbing. I have no clearance problems except when the wheel are turned completely to the right, then the tire rubs the pitman arm off the stearing box. I am not real concerned with this rub.

I will say that I wish I had gone with a slightly longer front stud, with the 1/4" spacer and the thicker mounting flange of the aluminum wheel there is just enough stud left on the front to safely install the lug nuts, if I had looked for a stud about 3/8" longer I would have run 1/2" spacers on the front and not had to grind on the tie rod ends. But, hindsight is always 20/20.

Hope this helps, if you plan on doing this mod, remember to take your time and drill the holes as straight as you can. I took 3 full days to do this just so I made sure not to mess it up.

If you have any questions PM me or post here and I will try to answer them.

Woody

[edman87]

With the spacers, be sure to re-tighten your lugs regularly. I have heard horror stories of lugs working loose with spacers and even worse with adapters.