installing 351M
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installing 351M
Hi Everyone, just registered, looks like I've found a great sight for info! My question is I have a 84 F/S Bronco with a 300 I/L 6 cyl. and have found a donor 78 Bronco with a 351m in it. Both have standard trannies but I would like to keep the tranny that I have 4spO/D. How much work is involved swapping a six to an eight and will it bolt to my existing tranny? I asked a transmission guy and he said it would bolt right on without making any changes.
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From: PacNW
Welcome to FTE.
Unfortunately your tranny guy is wrong. The 351M doesn't have the same bellhousing bolt pattern as the 300. You'd need to swap bellhousings or find a 351W motor. The 6 to 8 swap shouldn't be too tough but I'd get as many of the motor mount pieces out ot the V-8 truck as I could. Some may not work since the 84 Bronco never came with a 351M but it's better to have too many than too few.
Unfortunately your tranny guy is wrong. The 351M doesn't have the same bellhousing bolt pattern as the 300. You'd need to swap bellhousings or find a 351W motor. The 6 to 8 swap shouldn't be too tough but I'd get as many of the motor mount pieces out ot the V-8 truck as I could. Some may not work since the 84 Bronco never came with a 351M but it's better to have too many than too few.
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From: Indiana
bronc84
You will at least need the engine frame mounts. These will work from an 80-82 Bronco, F-150, F-250, F-350, that had 351M or 400's in them.
Transmission, I don't know about, other than that the O/D unit was maybe not very strong. My brother in-law had one in an early 80's F-150, 4x4 with the 300 inline 6 and some bearing kept wearing through the case on it. He put two of these transmissions in that truck. Got rid of it when the second one started to puke.
You will at least need the engine frame mounts. These will work from an 80-82 Bronco, F-150, F-250, F-350, that had 351M or 400's in them.
Transmission, I don't know about, other than that the O/D unit was maybe not very strong. My brother in-law had one in an early 80's F-150, 4x4 with the 300 inline 6 and some bearing kept wearing through the case on it. He put two of these transmissions in that truck. Got rid of it when the second one started to puke.
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The main bearing was gone when I replaced the clutch. Could I Keep the 78' 351m and its tranny together to drop in? Will it match the rest of my drivetrain? What type of manual trannies came stock with the 78's? Thanks again for all the info so far.
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From: Indiana
You may be able to use the whole chunk. I had an 81 F-150 4x4 with the 300 i-6 myself that once had that O/D manual in it and the P/O had swapped it to a regular truck four speed. You could not tell it did not belong there.
Speedo worked fine and everything. I don't know what it entailed, but nothing looked cobbled.
Speedo worked fine and everything. I don't know what it entailed, but nothing looked cobbled.
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