1974 BB Distributors
Thread Starter
Instructor
Joined: Dec 2024
Posts: 123
Likes: 28
From: Chicago Burbs
1974 BB Distributors
Quick question:
Does a normal AC Delco HEI distributor fit without interference with the fire wall? This is specific to the 454 BB - I'm thinking no since even the original points distributor vacumm cannister has limited space between the fire wall.
I ask cause, I have access to a bunch of 75-76-77's on Friday & i have the ability to scavenge some parts - none are BB's
I dont't want to grab one if it wont fit.
Does a normal AC Delco HEI distributor fit without interference with the fire wall? This is specific to the 454 BB - I'm thinking no since even the original points distributor vacumm cannister has limited space between the fire wall.
I ask cause, I have access to a bunch of 75-76-77's on Friday & i have the ability to scavenge some parts - none are BB's
I dont't want to grab one if it wont fit.
Race Director
Joined: May 2006
Posts: 18,734
Likes: 2,582
Quick question:
Does a normal AC Delco HEI distributor fit without interference with the fire wall? This is specific to the 454 BB - I'm thinking no since even the original points distributor vacumm cannister has limited space between the fire wall.
I ask cause, I have access to a bunch of 75-76-77's on Friday & i have the ability to scavenge some parts - none are BB's
I dont't want to grab one if it wont fit.
Does a normal AC Delco HEI distributor fit without interference with the fire wall? This is specific to the 454 BB - I'm thinking no since even the original points distributor vacumm cannister has limited space between the fire wall.
I ask cause, I have access to a bunch of 75-76-77's on Friday & i have the ability to scavenge some parts - none are BB's
I dont't want to grab one if it wont fit.
Last edited by MelWff; Nov 24, 2025 at 05:14 PM.
Drifting
Joined: Jun 2025
Posts: 1,715
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FWIW: No OE GM HEI distributor has a mechanical cable tach drive; None. HEI w/ tach drive are aftermarket only. All GM coil-in-cap HEI caps have an OD that's Much larger than points cap OD.
Might require a '75-up OE air cleaner assembly for the Much-larger diameter HEI dist cap to not bind. Or some aftermarket air cleaner assembly. The OE HEI air cleaner assembly bases have substantial flat "dent" to afford clearance for HEI cap. Also, some amateur oval track race air cleaner bases for 14" filters have a substantially offset opening for carb AND a "crooked bent" threaded rod for lid. It essentially moves entire air cleaner assembly Forward (in reference to threaded hole in carb) an inch or so. Speedway, Allstar etc sells those.
Might require a '75-up OE air cleaner assembly for the Much-larger diameter HEI dist cap to not bind. Or some aftermarket air cleaner assembly. The OE HEI air cleaner assembly bases have substantial flat "dent" to afford clearance for HEI cap. Also, some amateur oval track race air cleaner bases for 14" filters have a substantially offset opening for carb AND a "crooked bent" threaded rod for lid. It essentially moves entire air cleaner assembly Forward (in reference to threaded hole in carb) an inch or so. Speedway, Allstar etc sells those.
Thread Starter
Instructor
Joined: Dec 2024
Posts: 123
Likes: 28
From: Chicago Burbs
This BB likes about 14 deg initial to run good, and close to 35 above 2500
Question remains - will it fit?
Theres less than an inch between the firewall and the housing, this also has the mechanical tach drive that has to be close in alignment.
Yes..... Sure I can reset (Clock) the unit but I dont' want to go through the hassle of imposing on my friend for a dissy that ultimately doesn't fit.
The distributor is original and is past due for a rebuild.
Race Director
Joined: May 2006
Posts: 18,734
Likes: 2,582
This BB likes about 14 deg initial to run good, and close to 35 above 2500
Question remains - will it fit?
Theres less than an inch between the firewall and the housing, this also has the mechanical tach drive that has to be close in alignment.
Yes..... Sure I can reset (Clock) the unit but I dont' want to go through the hassle of imposing on my friend for a dissy that ultimately doesn't fit.
The distributor is original and is past due for a rebuild.
You can buy an aftermarket with a cable drive tach.
