Worn out 300 replacement
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Junior Member
Joined: Mar 2018
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From: SW Missouri
Worn out 300 replacement
I'm replacing my 300 6cyl in a 76 F150 frame with a 302 block (351 Windsor) and wanting to know if it will mount to the existing frame horns. Will the current radiator be enough to keep the V8 cool?
Senior Member
Joined: Oct 2016
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From: Parts Unknown
I can't see how a 351 v-8 will slip in painlessly where a long 300 inline once resided.I could be wrong. Myself, I would put another 300 in there or rebuild what you got if the rest of the truck is rust free..
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Joined: Jan 2018
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From: Memphis, TN, Earth, Milky Way
The frame "horns" are at the front & rear ends of the frame, where the bumpers attach. The engine mounts attach to the engine perches, which (on '80-96 frames) are different for V8 vs. I6. To swap, rivets must be ground/cut/drilled/punched, and the correct perches bolted on.
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The radiator is about the same size, but the nipples are reversed for V8 vs. I6, so you'll be replacing it no matter what. There will undoubtedly be other differences you'll have to deal with.
BTW
A 302ci block isn't a 351W block, and neither one makes a helluvalot more power or torque than a 300ci. They do spray more gas out the tailpipe, though. And the 351W weighs more, so you lose some of its performance just getting the truck moving. I recommend swapping to a 4.9L (EFI) - it will be a performance AND economy improvement while fitting the original perches (and takes less maintenance, and is more reliable/durable). It's more work, but it's worth it.
(phone app link)
The radiator is about the same size, but the nipples are reversed for V8 vs. I6, so you'll be replacing it no matter what. There will undoubtedly be other differences you'll have to deal with.
BTW
A 302ci block isn't a 351W block, and neither one makes a helluvalot more power or torque than a 300ci. They do spray more gas out the tailpipe, though. And the 351W weighs more, so you lose some of its performance just getting the truck moving. I recommend swapping to a 4.9L (EFI) - it will be a performance AND economy improvement while fitting the original perches (and takes less maintenance, and is more reliable/durable). It's more work, but it's worth it.
Last edited by Steve83; Oct 6, 2019 at 09:23 AM.
