300 to 351M

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Apr 23, 2009 | 11:49 AM

ford_man

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From: Central Illinois

300 to 351M

I was wondering how much work would be involved if i wanted to swap out my 300 I6 and put a 351 M in instead. It is a 1979f150 4x4, with a 4 speed tranny. I just want to know what all has to be changed, on the truck

thanks

daniel

Apr 23, 2009 | 03:13 PM

Kemicalburns

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From: Bend,OR

need frame towers, motor mounts, v8 radiator, 351m-400 bellhousing, new clutch.

why is the next question?

Apr 23, 2009 | 04:19 PM

85e150

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If you are going to put in a stock 351m, you are going to a lot of work for not much gain. If you are going to put in a stock 351m with xx,000 or xxx,000 miles on it, you are wasting your time and money.

You could freshen up the 300, add a few extras, and be back on the road quicker, for probably less money, and what money you do spend goes to making the engine run better vs. making it fit.

jmo, ymmv

Apr 30, 2009 | 08:38 PM

havi

I'll have the Roast Duck

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From: Northshore, MN

I did the opposite in my '79 Bronco. Frame mounts, throttle cable, radiator, bellhousing/tranny, radiator support may be different, exhaust (obviously, lol), and maybe a couple other things I'm forgetting. For a stock 351M, the 300 is about the same for HP and torque, IMO. 351M is a bit higher in torque, but a bit less in mpg. All in all, you can see it's not a simple bolt in affair. If you do do the swap, I'll gladly take those frame perches off yer hands.

May 9, 2009 | 09:17 AM

zstangkrewson

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From: west plains, missouri

there is quite a difference between the v8 and the straight 6, they drive completely different, the torque is different between them and the power curve i feel is alot more aggressive in the v8, i am fixing to do this swap except im putting a 302 in place of the 300-6 . . . my only concerns is wiring... as for the radiator, why would i have to change out the radiator from the 30-6 if im replacing a 302 in its pplace, the cubic inches are similar... should be sufficient right???