76rckt455

Ok here is the issue i have a 455 in my 76 cutlass with headers. I trimmed the lower Alt bracket to fit the headers, but i cannot get the bolt to line up with the mounting hole. I tried just installing the bolt without the bracket still wont line up. Would elongating the hole effect header gasket seal ??

64Rocket

Any chance you can get some pic's?
Gene

76rckt455

sure when i get started in the morning I'll snap a few

2blu442

I believe the late 1970's engines had a large aluminum bracket that doesn't need to bolt up to the exhaust manifold bolt. Gene, does that sound familiar to you or am I remembering wrong John

joe_padavano

No, you're thinking of the 307s. The 70s motors still used the stamped steel brackets.

EDIT: Well, maybe the late 70s SBOs used that bracket also. I'm not completely sure. In any case, that's only the bottom of the alternator. There is still the stamped steel upper part that does bolt to the PS pump bracket and the manifold bolt.

2blu442

Would that work for him Joe? Would that provide a bracket that would bypass the fastener point at the exhaust manifold? Then I guess another consideration would be pully alignment. Would the alternator pully be in a different location than the stamped steel brackets? John

OK.... I replied too soon! I know I have a large aluminum bracket that came off a 1978 Toro with a 403. Then I've got a different big aluminum bracket that came off a 455 that had been installed in a 1978 Cutlass so I don't know what that bracket came off of. I didn't remember them having a lower bracket still... so much for my memory!

joe_padavano

Well, here's a picture of the 307 brackets on a 455. Note the finger pointing to the bottom stamped steel bracket, which still bolts to the exhaust manifold bolt. The aluminum bracket is only the pivot point for the alternator. There still needs to be another bracket that locks the belt tensioning adjustment. There's also no reason why the stock brackets won't bolt up with headers, so let's all wait for photos.

76rckt455

thanks for all the info, if u use the alt bracket for a 307 would i have to use the rest of the brackets for pulley alignment? Mike

joe_padavano

It depends on the water pump length and pulleys that you have now. The PS pump bracket is the same on both. While it's certainly possible to select the right pulleys and brackets to make this work, there are many, many threads here and on other boards where this accessory drive mix-and-match never ends well.

More importantly, if you can't get the current bracket to fit, this one won't either. Figure out the problem before throwing money at it. There is no reason why the stock bracket shouldn't bolt up. Photos would still help.

76rckt455

I think i figure out the problem, the lower bracket was bent slightly. Nothing a quick dig through my pile-o-parts couldn't solve

Texas Jim

joe_padavano

While I'd love to take credit, that's not mine. I stole that image from the web.

BIGJERR

I dont run the bar that goes to the back of the alternator to the top bracket......i do have my hole elongated some in the bottom bracket just to make it easier to get stuff back toghter......
Never had a problem throwing belts or anything also.........