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  76 cobra motor swap 302 to 351w

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Author Topic:   76 cobra motor swap 302 to 351w
dave76
Journeyman

Posts: 2
From:
Registered: Mar 2003

posted 03-01-2003 10:41 PM     Click Here to See the Profile for dave76   Click Here to Email dave76     Edit/Delete Message   Reply w/Quote
i am tryin to put a 351w in a 76 cobra 2 it had a 289 in it. can anyone tell me about any problems i might get into. and if i can use headers.

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Percy Hazel
Journeyman

Posts: 51
From: Bellingham, WA, USA
Registered: Jul 2000

posted 03-02-2003 03:11 AM     Click Here to See the Profile for Percy Hazel   Click Here to Email Percy Hazel     Edit/Delete Message   Reply w/Quote
Hedman makes swap headers

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perce111
78T-Top...IAM TOO

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Mike Patterson
Journeyman

Posts: 34
From: Huachuca City, AZ, USA
Registered: Mar 2001

posted 03-02-2003 10:29 AM     Click Here to See the Profile for Mike Patterson   Click Here to Email Mike Patterson     Edit/Delete Message   Reply w/Quote
The swap is pretty basic as long as you have the right parts.

1. You need a front sump pan for a 351W (the 351W takes a unique pan that is different from the 302 pan). Depending on the pan you use it may need to be dinged it a little bit where it goes over the rack. (I just saw someone advertising 351 "spacers" on E Bay this morning. They are basically just two 1/2" plates that bolt between the motor mounts and engine. I personally would avoid these due to the possibility of drive shaft angle and fan shroud clearance problems, but who know they might work).

2. Depending on the year of the engine your using, you may need another balancer and flexplate/flywheel. Around 1980 Ford changed the balance on the 302s and 351s from 28 to 50 oz. You must match the componets to your specific engine.

3. The 351W is a little taller and wider than the 302/289. You will need a 351W intake, and you may find out that aircleaner clearance is a problem. Most people either use a low profile air cleaner or hood scoop.

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dave76
Journeyman

Posts: 2
From:
Registered: Mar 2003

posted 03-02-2003 11:10 AM     Click Here to See the Profile for dave76   Click Here to Email dave76     Edit/Delete Message   Reply w/Quote
it is a 71 model 351w. and i just bought a double sump oil pan i change cars in the middle of the rebuild. from a 85 thunderbird to a 76 cobra. can you tell me if the oil pan i got will work. and i got two sets of headers long and short. both fit mustangs but i don't know what yr

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Mike Patterson
Journeyman

Posts: 34
From: Huachuca City, AZ, USA
Registered: Mar 2001

posted 03-02-2003 12:42 PM     Click Here to See the Profile for Mike Patterson   Click Here to Email Mike Patterson     Edit/Delete Message   Reply w/Quote
As far as I know the double sump will not work. As far as the headers you have, unless they are for a mustang II, or Pinto, chances are they will not fit in the tight engine compartment.

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windsoreight
Journeyman

Posts: 36
From: Ocean City, MD
Registered: Sep 2002

posted 03-03-2003 01:57 PM     Click Here to See the Profile for windsoreight   Click Here to Email windsoreight     Edit/Delete Message   Reply w/Quote
THe pan most definatly won't work. I went with a motorsports front sump pan for Mustangs Unlimited. I think it was right around $45. I actually bought it for my 68 but worked great for the MII, plenty of clearance. If the motor is going to stay relatively stock then go with manifolds. Your choice on headers is slim. Hedman make a set but have heard complaints about ground cleanance. I am running a set of Hooker super comps for a pinto and they are a major pain in the but. They go throught the fenderwell and are tight on the strut rods. Both choices are in the 450-500 price range. Low profile air cleaner should work with the stock intake. Good luck and it is nice to see some action on this forum.

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george thomas
Journeyman

Posts: 14
From: roanoke,va.,usa
Registered: Apr 2003

posted 04-27-2003 09:08 AM     Click Here to See the Profile for george thomas   Click Here to Email george thomas     Edit/Delete Message   Reply w/Quote
a freind of mine put a 351w in a must two and was able to use 302 headers (so he said ) they looked identical to mine so maybe they were ,just try to avoid the ones that go in front of steering rack and then back. i have always used hedman they fit fine in a 302.maybe they have 351w specific header.as far as oil pan if you or someone you know is a good welder you can modify a 351w pan for whatever you need it to do as long as it is a front sump.
george

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a351must2
Gearhead

Posts: 320
From: Snohomish, WA, USA
Registered: Jun 99

posted 05-02-2003 11:26 AM     Click Here to See the Profile for a351must2   Click Here to Email a351must2     Edit/Delete Message   Reply w/Quote
If you user the II manifolds, they will be extremely tight/won't fit on the passenger side. I've done it twice using stock manifolds with the ribs ground off to clear the frame rails. One person I know of centered the engine which solves the clearance problem on the passenger side and make it much tighter with the sterring shaft.

The pan has to be a front sump pan. My original pan was from a 351W Mercury and I later switched to a Milodon 8qt pan. I run a manual rack which does not have any clearance problems.

The Headman headers run all 8 tubes under the crossmember...lots of room for squishing pipes on the street. I've also heard that the Headman headers require using a motor plate because they run right through the stock motor mounts.

I've got Hooker Super Comp. 351W Pinto headers on mine and they are a pita. They run two tubes through the fender well on each side. The fender well tubes are very tight with the suspension and especially the strut rods. They also run right into the power brake master cylinder, but fit fine with manual brakes. I've heard they require modification to work with air conditioning too. In my case, the headers have been chopped up and reassembled to clear the power brakes and suspension pieces. They were also tucked up and centered to run through the double-hump tranny crossmember properly. There are slip fit tubes on both sides to ease installation...the shop that worked on mine also put 2-bolt flanges in place of the slip fittings which makes the headers much quieter. Almost forgot the headers will work with a C4 or Mustang II 4-spd, but need modified to clear the T-5 or SROD bellhousings. All in all, the headers plus dual 3" exhaust ended up over $1200.

Hood clearance also becomes an issue if you run anything other than a factory 2-bbl or 4-bbl intake. I can't even guarantee that the 4-bbl intake will work, but the 2-bbl barely fits under the hood with a 1" EGR spacer under it. My 4-bbl 351W has a Performer RPM intake and Holley 4150 4-bbl and pokes out of the hood.

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Darryl Lang
http://www.a351must2.atfreeweb.com
'76 Coupe, 351W C4
'77 Mach 1, 5.0L HO 5spd
'78 T-Top, 351W Tremec
'78 Coupe, 2.3L Turbo 5spd

[This message has been edited by a351must2 (edited 05-02-2003).]

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cobraii351
Journeyman

Posts: 58
From: Altoona, PA
Registered: Jun 2000

posted 05-02-2003 03:05 PM     Click Here to See the Profile for cobraii351   Click Here to Email cobraii351     Edit/Delete Message   Reply w/Quote
Hey Mike, I don't know who gave you the info on the balance changes on the 351 but FORD NEVER changed the balance of the 351. only the 302/5.0.

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76 Cobra II
351W powered
C90x "shelby" intake
Ported D0OE heads
Holley 600

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