Alternator clash with Tall Valve covers - Solution
Thread Starter
Instructor
Joined: Feb 2006
Posts: 118
Likes: 25
From: Killearn Scotland
Alternator clash with Tall Valve covers - Solution
Once I’d fitted tall valve covers, I could never get enough adjustment to fit and tension my fan belt with my stock ’76 alternator set up.
The engine is a 383 with a big cam, and I needed to massage the short style covers (with a 4lb hammer) to prevent some of the rockers touching.
I searched the forum for solutions to this, and just found other people with the same problem of alternator clearance when trying to use tall valve covers.
All the fixes were by returning to short covers, with some people using two or more gaskets!
I thought trying to get those gaskets to seal one at a time was bad enough, and stacking gaskets doesn’t sound like a good long term engineering fix.
It turns out the answer is simply to use the later style lower alternator bracket (GM Part #14015510). This is an aluminium bracket as opposed to the original iron lump, which is a bonus.
The stock upper bracket also required replacing as it no longer fitted past the slightly thicker lower mount. Fortunately a Universal arm from Jegs (#778-66115) works perfectly, but needed mounted onto the lower bracket bolt as opposed to the water pump bolt. That, and a slightly longer belt (SPA-1410 (metric size)) and I have an alternator that clears my tall covers, and allows belt tensioning.
Here we have a slightly scruffy but practical engine bay with new alternator brackets. The empty pulley groove is for the long-gone Air Conditioning. This is Scotland after all
And this is a close up of the clearance between alt and valve cover. The actual gap is about 1/2".
The engine is a 383 with a big cam, and I needed to massage the short style covers (with a 4lb hammer) to prevent some of the rockers touching.
I searched the forum for solutions to this, and just found other people with the same problem of alternator clearance when trying to use tall valve covers.
All the fixes were by returning to short covers, with some people using two or more gaskets!
I thought trying to get those gaskets to seal one at a time was bad enough, and stacking gaskets doesn’t sound like a good long term engineering fix.
It turns out the answer is simply to use the later style lower alternator bracket (GM Part #14015510). This is an aluminium bracket as opposed to the original iron lump, which is a bonus.
The stock upper bracket also required replacing as it no longer fitted past the slightly thicker lower mount. Fortunately a Universal arm from Jegs (#778-66115) works perfectly, but needed mounted onto the lower bracket bolt as opposed to the water pump bolt. That, and a slightly longer belt (SPA-1410 (metric size)) and I have an alternator that clears my tall covers, and allows belt tensioning.
Here we have a slightly scruffy but practical engine bay with new alternator brackets. The empty pulley groove is for the long-gone Air Conditioning. This is Scotland after all
And this is a close up of the clearance between alt and valve cover. The actual gap is about 1/2".
Melting Slicks
Joined: Apr 1999
Posts: 2,675
Likes: 13
From: Sudbury MA
Excellent solution to this problem.
I had similar problem on my 68 back in 1972 when I first bought it as it had the Mickey Thompson tall finned valvecovers and the alternator would hit the corner of the cover.
I completely restored the car so now I am back to using the small valve covers and everything fits well.
Your remedy is an excellent solution for those using the tall covers.
Kurt
I had similar problem on my 68 back in 1972 when I first bought it as it had the Mickey Thompson tall finned valvecovers and the alternator would hit the corner of the cover.
I completely restored the car so now I am back to using the small valve covers and everything fits well.
Your remedy is an excellent solution for those using the tall covers.
Kurt
this is what i did with mine, 55 1/2" belt and plenty of clearance
1st Gear
Joined: Jun 2026
Posts: 1
Likes: 0
From: Near Seattle WA
Do you happen to have the model number of the belt you used? I'm having the same issue. Tried a 56" belt and it was too large. I was gonna try the MasterPro 7545 (55-5/16") tomorrow.
