Swapping an inline 6 for a V-8
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Junior User
Joined: Apr 2004
Posts: 81
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From: Kirkland, WA
Swapping an inline 6 for a V-8
Hi All,
Newbie here. First round's on me!
I have a new (to me) '85 F250 with the 300ci inline 6. I like the truck, but the motor does not have nearly enough oomph to pull my 21 ft toy hauler over the passes around here. I'm down to 20- 30 mph in many sections. It is very embarrassing to get passed by a loaded down VW bus!
Even the slightest incline slows me to 45mph or below.
I have a friend with a fresh 302 (less than 100 hours) that is in a boat he's junking. I can get that motor for free and would only need the correct pressure plate water pump, brackets, etc. (not sure exactly what I will need) This motor has the marine (torque) cam and will hopefully pull a bit harder than the straight-6.
Any info would be greatly appreciated. (I did a search and didn't find much that I could use)
Thx - Drew
Newbie here. First round's on me!
I have a new (to me) '85 F250 with the 300ci inline 6. I like the truck, but the motor does not have nearly enough oomph to pull my 21 ft toy hauler over the passes around here. I'm down to 20- 30 mph in many sections. It is very embarrassing to get passed by a loaded down VW bus!
Even the slightest incline slows me to 45mph or below. I have a friend with a fresh 302 (less than 100 hours) that is in a boat he's junking. I can get that motor for free and would only need the correct pressure plate water pump, brackets, etc. (not sure exactly what I will need) This motor has the marine (torque) cam and will hopefully pull a bit harder than the straight-6.
Any info would be greatly appreciated. (I did a search and didn't find much that I could use)
Thx - Drew
Tuned
Joined: Sep 2003
Posts: 401
Likes: 9
From: Brighton, IL
IMO the six should do a fine job. I can pull 5-6K lbs. without a strugle. My guess is you have to high of gear in the rear end. What axle code do you have on the sticker in the driverside cab door opening? A 302 would not pull as good as the 300. You might even have a bad catalytic convertor.
Thread Starter
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Junior User
Joined: Apr 2004
Posts: 81
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From: Kirkland, WA
Update
I'll check the codes tonight. I however don't think it is geared too high. Here's the limited knowledge I have of this truck so far.
F250 HD (8,500LB)
300 ci I-6 (carb model)
4-Speed Tranny w/compound low
it tops out at about 70mph with the motor just wailing. It prefers to drive at 60mph which is ok with me if it would consistently go that fast with the trailer. My trailer weighs XXX dry and about XXX loaded. I'm down to about 40mph on a 3% (or less) grade.
F250 HD (8,500LB)
300 ci I-6 (carb model)
4-Speed Tranny w/compound low
it tops out at about 70mph with the motor just wailing. It prefers to drive at 60mph which is ok with me if it would consistently go that fast with the trailer. My trailer weighs XXX dry and about XXX loaded. I'm down to about 40mph on a 3% (or less) grade.
Freshman User
Joined: Sep 2003
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From: Fridley,MN - N.Mpls
Offenheimer makes an intake manifold and Carb (I think), where you can get 300 hp out of a 300 six. lotta oomph for a 6. buddy of mine was telling me about it in one of his truck magazines.
FTE Chapter Leader
Joined: May 2002
Posts: 42,877
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From: Fraziers Bottom, WV
I drive a 1982 F250, 4x4, 300 l6, 3.54 front and rear with 200,000 miles. I pull a 4200 # gooseneck horse trailer with 1200 # horse and another 500 # of gear. It does drag down on a steep hill from 70 - 60, but I don't need to down shift. My friend drives a 77, 1 ton duely, 454 cid and 4:10 gears. He also pulls down on the hill and has to down shift!
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Logistics Pro
Joined: Jan 2002
Posts: 3,739
Likes: 3
From: GANS
You won't be getting much by swapping from a 300 to a 302. Plus, the motor in the boat could be reverse rotation.
If you need more power, I wouldn't be considering anything less than a 351W with a few mods.
If you need more power, I wouldn't be considering anything less than a 351W with a few mods.
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Thread Starter
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Junior User
Joined: Apr 2004
Posts: 81
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From: Kirkland, WA
Yeah, I've decided to keep the I-6 300 and just do the basic power mods. I've picked up the EFI exhaust manifolds and a Clifford intake manifold. I am now waiting for the Walker downpipe to arrive.
I still need to find a carb, but finances require that I wait a bit.
Anybody have recommendations for a 2 bbl carb?
I still need to find a carb, but finances require that I wait a bit.
Anybody have recommendations for a 2 bbl carb?
Posting Guru
Joined: Jun 2001
Posts: 1,208
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From: Conyers
A 302 isn't exactly what I'd call a truck motor...towing will be alot worse. You'll need the motor mount perches from the frame, the flexplate or flywheel, radiator (the radiator outlets are different), and I think thats about all. Your best bet would be to find a nice 351 and pop it in there, you'll like it alot better. If you want to keep the six, get a cam, carb, headers, intake and you'll be set. As for that 302, it will work, just not worth the effort. 
Edit, just saw your post...a Motorcraft 2150 off a motor such as a 351 or 360 would work nicely.
Edit, just saw your post...a Motorcraft 2150 off a motor such as a 351 or 360 would work nicely.
