engine swap
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Freshman User
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From: butler, pennsylvania
engine swap
I have a 1981 F-150 how much work is involved in replacing my 300 six with a small block? The truck has a manual 4 speed in it. Do I have to change anything major or will it slip right in and one other thing what is the best small block to build 351 or a 302?
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From: Virginia
351 is best. You have to grind the motor mount perches off the frame, and go get ones you have ground off from a junkyard truck with a v8, and bolt them in place. Then theres little odds and ends like throttle cables and some wires, and a flywheel to match your v8 engine.
You can get a v8 from any Ford or Mercury car or truck, but you have to make sure it has a rear sump oil pan. Usually you have to go to the junkyard and get one of those too, with the matching dipstick, oil pump pickup, and the main bolt stud to hold the pickup in place.
You can get a v8 from any Ford or Mercury car or truck, but you have to make sure it has a rear sump oil pan. Usually you have to go to the junkyard and get one of those too, with the matching dipstick, oil pump pickup, and the main bolt stud to hold the pickup in place.
Post Fiend
Joined: Mar 2004
Posts: 24,418
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From: San Francisco, Ca.
If you change to a 351W, you need to change the engine brackets.
EOTZ-6028C
EOTZ-6029C
Not sure which is left or right.
I had the same idea, same truck, '81 F150 4.9L---- but.......................
sckootter578, Welcome to FTE.
EOTZ-6028C
EOTZ-6029C
Not sure which is left or right.
I had the same idea, same truck, '81 F150 4.9L---- but.......................
sckootter578, Welcome to FTE.
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Freshman User
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From: butler, pennsylvania
ok thanx is there a diffrence between 351 modified and the 351 winsor and how do you can you tell the diffrence between both? getting back to the sump pump basicly I a looking for a complete engine with oil pan and dipstick attached does the year matter? I plan on a total rebuild of the engine.
Post Fiend
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From: San Francisco, Ca.
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From: Virginia
The 351m has 8 bolts holding the valve cover on, and the 351w has 6 bolts on the valve cover.
The 351m will not bolt up to where the 300 six was, unless you get a different bellhousing. The 351w will bolt to the 300 bellhousing. The 351w is generally considered a better engine than the 351m.
If you want an engine that fits right off the bat, then stay with a 80-up truck or bronco engine. It will have the correct exhaust manifolds, and if you get the whole vehicle, you can get the y-pipe and all the other little things too.
The 351m will not bolt up to where the 300 six was, unless you get a different bellhousing. The 351w will bolt to the 300 bellhousing. The 351w is generally considered a better engine than the 351m.
If you want an engine that fits right off the bat, then stay with a 80-up truck or bronco engine. It will have the correct exhaust manifolds, and if you get the whole vehicle, you can get the y-pipe and all the other little things too.
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yea that y pipe is only about 300$ im gettin a 351w tomarrow guy says it came out of a 85 4x4 just like mine i have been lookin for a exhaust kit for it and stock exhaust is about 200+ with out the y pipe go with the 351w for sure
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if u run true duel u dont need the y pipe but will still need cats for the trucks exhaust dont think 80 is old enuff not to have them not sure tho a cat can run 40-90$ea depends on what u get really ive been told that it would be cheaper and sound lots better then goin with stock or tryin to fab a kit your self was told by a few part guys that a exhaust shop would be the way to go if u wanted true duels
Last edited by Kylet8020; Sep 14, 2007 at 03:41 AM.
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83 is the last year without cats to leagally pass but if you go into an exhaust shop make sure the sticker on the core support sould be on the left side of the hood catch is removed or they will not touch it because technically if it come from the factory with cats it has to always have cats so scrape it off and you can you should be fine
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Originally Posted by AlbraiNYa
what about his bellhousing, and pilot bearing or bushing that he will need??
srry had to edit its only true tho if he goes with a 351 windsor the 302 300 and 351w/ho used the same clutch starter and bellhousin
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