1978 F800
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1978 F800
I have a 1978 F800 (digger derrick) it idles a lot and tends to load up, i bought a new holley carb (without a governor). I was wondering if anyone has put a electronic ignition, or new/ different distributor to give it a little hotter spark. The truck does not get drove much but does a lot, just idle time.
Fleet Mechanic
Joined: Dec 2005
Posts: 1,603
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Float level too high, leaking float needle valve fuel pump pressure power valve leak. Distributor has nothing to do with loading or running rich. Not being nasty but new out of the box doesn't mean its turn key now a days.
1978 F800 most likely has a 4 barrel Holley on a 391 FT. I use to be a Holley freak then we have gone to Edelbrock 4 barrels for our 391s. what a difference. don't know where you are from but Holley's do not like
mid 30 degree and rain they load up they ice up black smoke ......................
1978 F800 most likely has a 4 barrel Holley on a 391 FT. I use to be a Holley freak then we have gone to Edelbrock 4 barrels for our 391s. what a difference. don't know where you are from but Holley's do not like
mid 30 degree and rain they load up they ice up black smoke ......................
Cargo Master
Joined: Dec 2015
Posts: 2,549
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From: Harned, Ky
389 would have had a 2 bbl carb.
389, 390, 391 are all the same cubic in engine.
389 FT with 2 bbl carb
391 FT engine with 4 bbl carb
390 FE engine for cars and pickups
Throw a Pertronixs electronic ignition in the distributor, the hotter spark will clear up most of the fuel loading issue.
It takes a hotter spark to burn todays gas, if it idles a lot and sees very little road use swap the cold burning plugs it uses for something hotter.
Don't remember the Autolite number but in Champion the truck takes F10's, we swapped over to F9Y's like was used in cars.
This was done on a 71 L800 with 391, it's used to move trailers around the lumber yard, idles a lot and hasn't been out on the highway in over 20 years.
389, 390, 391 are all the same cubic in engine.
389 FT with 2 bbl carb
391 FT engine with 4 bbl carb
390 FE engine for cars and pickups
Throw a Pertronixs electronic ignition in the distributor, the hotter spark will clear up most of the fuel loading issue.
It takes a hotter spark to burn todays gas, if it idles a lot and sees very little road use swap the cold burning plugs it uses for something hotter.
Don't remember the Autolite number but in Champion the truck takes F10's, we swapped over to F9Y's like was used in cars.
This was done on a 71 L800 with 391, it's used to move trailers around the lumber yard, idles a lot and hasn't been out on the highway in over 20 years.
Cargo Master
Joined: Dec 2015
Posts: 2,549
Likes: 331
From: Harned, Ky
That numbers no good
Mallory #MAA-3755301 is the dist for a Ford FE engine but will no work in a FT engine without installing a bushing in the block and and modified oil pump drive.
Mallory #MAA-3755301 is the dist for a Ford FE engine but will no work in a FT engine without installing a bushing in the block and and modified oil pump drive.
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Cargo Master
Joined: Dec 2015
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From: Harned, Ky
Guess the ones at the fertilizer plant had the intakes and carbs swapped out, not surprising they were bad about patching up stuff.
Those were the only trucks I ever saw with 389 labels on the air cleaner.
Had a couple of those engines out, they were the correct bore and stroke.
Those were the only trucks I ever saw with 389 labels on the air cleaner.
Had a couple of those engines out, they were the correct bore and stroke.
Super Moderator
Joined: Apr 2004
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Guess the ones at the fertilizer plant had the intakes and carbs swapped out, not surprising they were bad about patching up stuff.
Those were the only trucks I ever saw with 389 labels on the air cleaner.
Had a couple of those engines out, they were the correct bore and stroke.
Those were the only trucks I ever saw with 389 labels on the air cleaner.
Had a couple of those engines out, they were the correct bore and stroke.
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