Which distributor to get?

[grumpin]

I was so close not too long ago to getting an HEI for my truck. Good friend of mine has a 72 F100 with a pretty hot 302 and he's running an HEI. It scoots to say the least. Before I got the HEI another friend of mine convinced me to go with the MSD. He has a lot of experience with them in dirt track cars and said they never had a failure. I was battling parts store igniton modules as they were failing within days of install so when I heard the MSD would last a good while I jumped on it.

I know a lot of people that run HEIs and frankly they work good. But I can just hear all my GM friends taunting me if I popped my hood and there was an HEI front and center

Then tell them that’s where it should be! So a normal human can get to it!

 

[Ray Cecil]

I was so close not too long ago to getting an HEI for my truck. Good friend of mine has a 72 F100 with a pretty hot 302 and he's running an HEI. It scoots to say the least. Before I got the HEI another friend of mine convinced me to go with the MSD. He has a lot of experience with them in dirt track cars and said they never had a failure. I was battling parts store igniton modules as they were failing within days of install so when I heard the MSD would last a good while I jumped on it.

I know a lot of people that run HEIs and frankly they work good. But I can just hear all my GM friends taunting me if I popped my hood and there was an HEI front and center

Then tell them that’s where it should be! So a normal human can get to it!

Im a normal human, I can reach a chevy dizzy.....but I am 6'4"...so maybe I aint so normal.

[grumpin]

Im a normal human, I can reach a chevy dizzy.....but I am 6'4"...so maybe I aint so normal.

Ha! Good!

I used to reach the one on my 68 Chevy 1/2 ton I used to have. It had a 307. I could climb in there and sit.

The distributor on our Suburban is a bit of a challenge.

[Jacob84]

Then tell them that’s where it should be! So a normal human can get to it!

I do! but you know how they are...excuses excuses:nabble_smiley_whistling:

Then I remind them that my grandpa worked at the GM assembly plant in the 60s, and maybe some of the 70s, and even he didn't buy a GM truck because he didn't like how GM had them building the trucks! He went to Ford and bought a new 69 F100 390 FE, 3 speed on the column that he drove till the day he died!

I'm not a GM hater but I will give someone a hard time anytime I can:nabble_smiley_wink:

 

[85lebaront2]

Then tell them that’s where it should be! So a normal human can get to it!

I do! but you know how they are...excuses excuses:nabble_smiley_whistling:

Then I remind them that my grandpa worked at the GM assembly plant in the 60s, and maybe some of the 70s, and even he didn't buy a GM truck because he didn't like how GM had them building the trucks! He went to Ford and bought a new 69 F100 390 FE, 3 speed on the column that he drove till the day he died!

I'm not a GM hater but I will give someone a hard time anytime I can:nabble_smiley_wink:

Not every GM engine is a Chevy, Buick and Cadillac had front mounted distributors. The worst ones I used to get and hate with a passion were Pontiacs. In addition to sitting at an angle, it turns opposite the Chevy and Oldsmobiles and getting the wrench in the screw without getting knocked on your butt was damn near an exercise in futility.

My actual worst for access I owned was a 1957 312 in my 1958 F100, the battery on those trucks was on the right side of the firewall. a group 29NF and where it sat was about 3" from the distributor cap an the Y-block making point replacement loads of fun.

Back to the original thread, I used to sell both Mallory and when they came on the market Accel distributors, the difference in approach to high rpm point stability was interesting, Mallory got their start in the Flathead Ford era and their Rev-pol system showed it, two sets of points 45° apart in rotation, each working one end of a special coil which acted like two 4 cyl coils, the Double-Life distributor was the Rev-Pol distributor, wired for a normal coil. Their approach to limiting point bounce was simple, use very light points, thin stamped metal riveted to phenolic bearing blocks with a fairly light spring and on the Double-Life, 4 lobe cam so each point only opened 1/2 as often. We had an Allen 9K engine rpm distributor machine, my Mallory Double-Life would not show any anomalies in point behavior at 9K. Accel, took the opposite approach, using GM style points with very strong springs to achieve the same result, their big pitch was externally adjustable points, they also sold points for installation in your stock distributor. Their points in their distributor would start to show bounce at just over 8K, getting to total hash by 9K. Using their points in a stock distributor, plan on rebuilding or replacing it in just over 6-9 months as they would destroy the cam. At low rpm the advance was haphazard due to the spring load on rubbing blocks.

Mallory distributors used a vacuum brake, same thing Ford had before 1949, it retarded the mechanical advance at low manifold vacuum, letting the full advance come in at high vacuum. It was a very simple system, two plates with the centrifugal weights on the upper one, and a spring in an adjustable slot that with no brake would pull the upper plate into the desired advance, problem was it was an all or nothing event, once the vacuum retracted the brake piston, the advance went to the max vacuum at once unlike factory systems where it varied with vacuum. Accel at that point had no vacuum advance provision.

Since true electronic (breakerless) systems were in their infancy in those days (1970s) there were a number of aftermarket systems, I carried the Delta Mark 10 CDI systems, they used points to trigger them and a capacitor charged to 400 VDC to fire a stock coil and used a .060 plug gap. We found that due to the aggressive advance curve used by Chrysler that they were prone to misfire condition at highway cruise speeds. Delta released the Mark 10B specifically to address this, it used a variable duration spark. As Detroit went to breakerless ignition systems starting with Chrysler then everyone following with their own system. GMs was the cheapest and quickest to add, a self contained unit for most engines (the rear drive V6 S10 had a separate coil due to clearance problems), Chrysler's was the most problematic, extremely sensitive to reluctor air gap, Ford's initial Duraspark wasn't super either, and AMC used a Motorola built unit that was very reliable, but the distributor vacuum advance was an over engineered PITA with both a vacuum and barometric chamber in the advance, they failed if you looked them hard.

The GM HEI has one main problem, it is a current hog, needing a 10ga feed wire from a solid battery source. GM built this into their cars, using a real, not Chinese HEI unit in another brand really needs a relay to tap the battery positive side directly.

[Jacob84]

Not every GM engine is a Chevy, Buick and Cadillac had front mounted distributors. The worst ones I used to get and hate with a passion were Pontiacs. In addition to sitting at an angle, it turns opposite the Chevy and Oldsmobiles and getting the wrench in the screw without getting knocked on your butt was damn near an exercise in futility.

My actual worst for access I owned was a 1957 312 in my 1958 F100, the battery on those trucks was on the right side of the firewall. a group 29NF and where it sat was about 3" from the distributor cap an the Y-block making point replacement loads of fun.

Back to the original thread, I used to sell both Mallory and when they came on the market Accel distributors, the difference in approach to high rpm point stability was interesting, Mallory got their start in the Flathead Ford era and their Rev-pol system showed it, two sets of points 45° apart in rotation, each working one end of a special coil which acted like two 4 cyl coils, the Double-Life distributor was the Rev-Pol distributor, wired for a normal coil. Their approach to limiting point bounce was simple, use very light points, thin stamped metal riveted to phenolic bearing blocks with a fairly light spring and on the Double-Life, 4 lobe cam so each point only opened 1/2 as often. We had an Allen 9K engine rpm distributor machine, my Mallory Double-Life would not show any anomalies in point behavior at 9K. Accel, took the opposite approach, using GM style points with very strong springs to achieve the same result, their big pitch was externally adjustable points, they also sold points for installation in your stock distributor. Their points in their distributor would start to show bounce at just over 8K, getting to total hash by 9K. Using their points in a stock distributor, plan on rebuilding or replacing it in just over 6-9 months as they would destroy the cam. At low rpm the advance was haphazard due to the spring load on rubbing blocks.

Mallory distributors used a vacuum brake, same thing Ford had before 1949, it retarded the mechanical advance at low manifold vacuum, letting the full advance come in at high vacuum. It was a very simple system, two plates with the centrifugal weights on the upper one, and a spring in an adjustable slot that with no brake would pull the upper plate into the desired advance, problem was it was an all or nothing event, once the vacuum retracted the brake piston, the advance went to the max vacuum at once unlike factory systems where it varied with vacuum. Accel at that point had no vacuum advance provision.

Since true electronic (breakerless) systems were in their infancy in those days (1970s) there were a number of aftermarket systems, I carried the Delta Mark 10 CDI systems, they used points to trigger them and a capacitor charged to 400 VDC to fire a stock coil and used a .060 plug gap. We found that due to the aggressive advance curve used by Chrysler that they were prone to misfire condition at highway cruise speeds. Delta released the Mark 10B specifically to address this, it used a variable duration spark. As Detroit went to breakerless ignition systems starting with Chrysler then everyone following with their own system. GMs was the cheapest and quickest to add, a self contained unit for most engines (the rear drive V6 S10 had a separate coil due to clearance problems), Chrysler's was the most problematic, extremely sensitive to reluctor air gap, Ford's initial Duraspark wasn't super either, and AMC used a Motorola built unit that was very reliable, but the distributor vacuum advance was an over engineered PITA with both a vacuum and barometric chamber in the advance, they failed if you looked them hard.

The GM HEI has one main problem, it is a current hog, needing a 10ga feed wire from a solid battery source. GM built this into their cars, using a real, not Chinese HEI unit in another brand really needs a relay to tap the battery positive side directly.

Thanks for that info Bill, learned a lot!

[Jacob84]

Thanks for that info Bill, learned a lot!

Good news! Was able to talk to Scott and he's getting me set up. Should have a new distributor headed my way at the beginning of the week!

[Gary Lewis]

Good news! Was able to talk to Scott and he's getting me set up. Should have a new distributor headed my way at the beginning of the week!

Excellent!

Did you happen to mention the forum and that we sent you? If so that may be why he was so happy to talk to me today.

[Jacob84]

Excellent!

Did you happen to mention the forum and that we sent you? If so that may be why he was so happy to talk to me today.

I sure did! He seemed happy to know that's how I found out about him! Very professional and knowledgeable. Looking forward to doing business with him:nabble_anim_handshake:

[Rusty_S85]

I recommend Scotty Johnston, aka The Mad Porter. He runs Parkland Performance Auto Machine. He built my short block and several of us have purchased distributors from him. You tell him what you have and he sets a new dizzy up with the right curve, inc vacuum advance, for your truck and usage.

Tell him I sent you. And, he's a member on here. This is his introduction thread: http://forum.garysgaragemahal.com/New-forum-member-td43238.html#a43345

That is who I emailed last year for recurving my distributor.

Part of the email said the following. "We need full engine build specs, vehicle, trans, gearing, stall and intended use."

I provided the information as best as I could but told him I would give more precise specs once I finalize my 306 build. He told me the brand new Cardone 86 mustang 302 distributor with the steel gear is a good distributor but that the advance mechanism needed to be welded up to get my distributor to 32* advance which would be ideal for my AFR heads.

$120+ return shipping is not a bad price to get a distributor spun up on a sun machine and have the advance curve set.