Alternator bracket woes for '68 327

[bhobbs]

Just found the list, looks like a lot of useful info.

Does anyone know what alternator bracket I should be using on my '68 GMC? I've got a 327 with factory air(so ac bracket is on passenger side, and alt. bracket is on driver side). I fried the wiring in the truck two years ago, and have finally gotten around to replacing most of the electric bits. I replaced the sketchy alternator I had with a one-wire "Si" style one, and at the same time, I replaced my headers with some Hooker headers that came with a mounting plate that comes off the front two bolts, and then has slots that the actual mounting bracket for the new alternator bracket to slide in. My problem is that the old upper mounting bracket(the one with the slide space for tensioning the belt) is almost at max extension, and the alternator is butted up against the mounting tab on the headers(it could swing free towards the fenders, but its restricted by the upper bracket, and can swing no further towards the engine). This will definitely put the alternator beyond the stock belt, and doesn't really give me enough room to tension the belt I don't think.

Any thoughts here? Since I moved to a newer alternator, is there a newer bracket I need to swipe from a later year? Any help is greatly appreciated, and thanks in advance.

Barry
'68 GMC Custom LWB

[krue]

I would just go to a good local part store and figure out what size belt will give you the adjustment you need. Just use some string or rope to see what would put you at the inner (engine) side of the adjustment bracket and get a belt that size.
Hope that helps.
BTW Welcome to the best truck( and everything else) site on the web!

[krue]

Oh yeah, post some pics of your truck when you get a chance (can't get enough GMC owners!)

[bhobbs]

Oh, you've asked for it now. I'll post a couple of pics tomorrow, but they certainly aren't pretty

But as to the alternator belt, a longer one may/may not fix my primary problem, which is that I won't have enough fiddle room to get it tight(I don't think) even if I do get the right size. I will give it a good try though, as it's preventing me from moving forward on this project.

I'll post pictures of the upper and lower brackets, before and after, so you can get an idea of what I'm up against.

Barry

[Tx Firefighter]

You should not use the lower bracket that bolts to the exhaust bolts.

The proper bracket bolts to the front of the heads and is made of cast iron. That will fix your problem.

[Tx Firefighter]

This is the closest picture I could turn up of one. Note it bolts to the head, not the exhaust bolts.

[krue]

I see your problem now. Here is a pic of the brackets you need. Hope this helps.

[krue]

Dang I hate my slow dial up!

[bhobbs]

Thanks for the pictures guys. It's very odd how different it is, and yet how similar. The original bracket I had(old alternator and headers), partially mounted the alternator on the headers(big cast iron things with special holes in the front for this purpose). My upper piece looks similar, but is a different thickness(much thinner across the wide part that has the slot in it). I've been trying to mount this to the same spot that it was in originally(special bolt through the water pump), and maybe THAT'S why I don't have the clearance I need. I'll look for new mounting positions on the head when I get home tonight! Thanks!

Barry

[tom hand]

Someone correct me if I am wrong, But I believe all those pics are of 350 set-ups....he's working on a 327 which has no holes in the heads, so those setups will not work. The simplest solution would be to go buy the correct upper bracket for the header bracket you already have....any parts store that carries Mr. Gasket stuff will have one hanging on the wall...Good Luck

[krue]

Well I learn something everyday. Thanks Tom for the info.

[Pilgrim]

My 68 327 has the upper alt bracket bolted to the upper water pump bolt (stud). The lower alt bracket is also bolted to the stud and to the exhaust manifold.

[BtnkBndt]

My 283 has no accessory holes either. I had no problems with the bracket I picked up at Autozone. Here is some not so good pics.

[thisolechevy]

Huh I am really out of the loop now!! My 327 has the same style bracket that btnkbndt has for the lower alt. bracket. But Instead of my upper arm connecting to the water pump it mounts to my aftermarker Edelbrock performer series low rise intake??? the only problem is that the alt tension bolt does not line up in the slide-slot instead it reaches to teh very end of the upper bracket and bolts to the end out of the slot?? wierd but works!

[bhobbs]

As mentioned, I believe the 350 and 327 heads are different(mine is a 327).

Picture of the alternator set in place with the old upper arm, on the Hooker bracket:


Picture of the alternator bracket. This is from the driver's side, and you can see how it mounts to the front bolts of the headers, comes up, and then sticks out with a pair of mounting holes. That whole assembly slides for and aft to line up the belt. This picture was prior to a trip to the hardware store for a longer bolt.


Here's a close up of the heads, the mounting point on the water pump, and the slide-adjust armature(just as proof we're not making it up):


Here's a close up of the engine-side of the Hooker alternator mount. If I had some more clearance to tilt the alternator towards the engine, I don't think I'd have a problem. However, I'm as far inboard as I can get it, so I need a different armature. The recommendation of getting a longer one from AutoZone is encouraging:


Thanks for the help guys, and any other recommendations are highly appreciated

Barry

[BtnkBndt]

Mine is like thisolechevy is describes. Goes from the intake to the alternator. They do have an upper arm at Autozone, it looks to also mount to the intake. If you look at the top view pic in my first post you can see the bends mine makes and bolts to the front of the alternator. The ones at autozone are flat and kinda flimsy but might work if you bolt the alternator from behind like you have it now. If your intake has a threaded hole up front it might work. My lower bracket is exactly like yours, probably all from the same manufacturer.

[EdB]

I was running the 264 or "humpback heads" on my truck. They don't have the
holes. I am still using the same setup as Bhobbs. I have extended the top brackets
by welding in a section to make it longer. I kept having trouble with the header
brackets breaking. I would have to buy a new one about every 6 months. I rewelded
a broke one about 10 years ago and it has not broken since. I built up the area
that was breaking. It is simple to do if you have access to a mig and hacksaw.
Hope this helps.
EdB

[bhobbs]

Just as a quick closure for anyone that runs across this thread:

Autozone carries a generic chrome alternator bracket with two mounting holes in the bottom which facilitate this changeover from the stock header-mounted alt. bracket. It's a little tight across the bottom of the sweep slot, but some quick grinding takes care of it. It's pretty cheap. You'll need a slightly longer belt, by about 3-4 inches, and if it's too long, you'll interfere with the other items in the front of the engine.

They also carry a matching bracket to the official Hooker part that mounts to the header bolts, but it doesn't look as durable as the one I have pictured above.

Barry