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swaping to 351

dave p

Jr. Member
Joined
Sep 12, 2019
Messages
52
Hello, my 302 is toast so I am thinking about installing a remanufactured 351W long block. Is this the best way to get a little more h/p and torque. Will my headman long tube header fit the 351W also will my intake manifold ,water pump and oil pan fit. also a good place to buy a dependable 351W long block or a slightly built 302. Thanks
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Headers are a sometimes fits. Can't comment specifically for the headman. The downstream exhaust typically needs slight adjustment as the heads sit higher and that moves the headers further apart and up.

Intake, distributor, and oil pan will not interchange. Timing chain forward will.

The added torque of the 351 is what makes it a win. Don't know anyone who has been disappointed in going from a 302 to a 351.
 
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dave p

Jr. Member
Joined
Sep 12, 2019
Messages
52
Thanks for the info, I forgot to add that I am installing a AOD that I've already purchased. the headers are ceramic coated so I don't think I can modify them very easily. Also I will be installing a whole new exhaust. Also thinking of going with fuel injection, is it worth the money ? If so what one is the best? Was think pro flow 4 or sniper. Thanks again for the help.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
I would say to mock it up on the floor before you install it. The AOD is wide and can create fit issues. This is one area where a 351 can help since it spreads the collectors wider apart.

I have ran a 351 (nicely built with aluminum heads) and ditched the headers for a set of K-code repop manifolds. The 289 hipo manifolds. Nicer than the normal logs, almost a shorty header. And easy to port match cast iron.

As for fuel injection you will find fans and haters. I am a fan. A good carburator is good, but a good one is hard to get.
Pro flow is a better EFI than the Sniper. Not that the Sniper is bad, just the pro flow is a nicer unit.
 

Madgyver

Bronco Madman
Joined
Jul 30, 2001
Messages
14,678
intake, distributor, oilpan are different between a 302 and 351W. cheaper available headers can be made to work by rotating the collector on passenger side.
 

ngsd

Contributor
Bronco Guru
Joined
Mar 2, 2019
Messages
2,531
I have a 351 FI with stock manifolds on my trail rig and love it. It is actually very nice doing slow trails and crawling without the deep rumble all day.
 

Big Ben

Newbie
Joined
Feb 19, 2018
Messages
6
Thanks for the info, I forgot to add that I am installing a AOD that I've already purchased. the headers are ceramic coated so I don't think I can modify them very easily. Also I will be installing a whole new exhaust. Also thinking of going with fuel injection, is it worth the money ? If so what one is the best? Was think pro flow 4 or sniper. Thanks again for the help.
Are you going with a roller block? If you do and decide to go with the Proflo 4 make sure you also order the correct distributor gear. I waited about 7-8 months to get my proflo in only to have to order the correct gear which is also back ordered.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
may have to deal with firing order and clutch mount depending on what year engine you get.
 

Big Ben

Newbie
Joined
Feb 19, 2018
Messages
6
Are you going with a roller block? If you do and decide to go with the Proflo 4 make sure you also order the correct distributor gear. I waited about 7-8 months to get my proflo in only to have to order the correct gear which is also back ordered.
May also have hood clearance issues if you don’t have a scoop or cowl already. 351 is taller
 

66ranger

Newbie
Joined
Aug 20, 2020
Messages
12
I put a 351 in my 68 in 1972, I had to cut the center brace out of the hood so it would clear the air cleaner. I also had to make a oil pan by cutting the top off the289 pan and the bottom off the 351 and welding them together. The headers were another adventure….Just because the vender says 289, 302, 351 don’t make it so.. Thiswas in the early days for broncoso we had to make do. Now we have many venders making lots of parts. I have since added a1 inch body lift in an effort to Clear the air cleaner along with an ax15. There is a pan kit available through CJ and I m going to see if it fits some time this winter.. The shorty headers fit with one exception, Ihad to put a 1/2 inch spacer under the right motor mount so the right side would clear the frame and since my 351 still had big spark plug, I had to grind the notches for the plugs ( front and rear, both sides). It’s worth the trouble, more torque and potential horse power.
 
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dave p

Jr. Member
Joined
Sep 12, 2019
Messages
52
Thanks for the info. Any thought about making the 302 a stroker 347?
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Thanks for the info. Any thought about making the 302 a stroker 347?
The expensive way of doing it.

There is a thread of 20 questions for stroker owners. There is one 347 user in that thread. And the comment that they should have done a 351 based engine.

351 swaps have been done since the early 70s. They are not hard to do. They work really well. If anything is difficult it is there are so many options for the little details. What accessory drive do you want to run? Which oil pan do you want to run? Which intake do you want to run? And the list goes on. Each choice usually has a second choice that follows it.

There are a handful of basics that have to match a 351. The rest of it is just a straight swap. The 351 has bigger bearings. So the back of the oil pan has a larger radius. Thus a 351 has a different pan than a 302. The deck height is taller, the heads are further apart, you need a wider intake manifold. Thus a 351 specific manifold. The oil pump driveshaft is larger, thus a 351 distributor to mate with the oil pump. All of these points are good upgrades. Bigger beefier bearings, taller deck height so a longer rod can be used, and the 302 oil pump drive is known to twist so bigger is better there as well. Most crate engines have some nice looking HP numbers. That is little more than the aftermarket heads (that also fit the 351) and a performance cam.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
I bought a running 96 E350 van with a 351W $850 I swapped it all over (modified the EFI and forced the front dress to work) I run the van pan because I have a 2.5 SL and am street only with a muddy road or two here and there.

The cheapest way to go EFI (IMO) is Snipper or FITech. Going EFI on a W is expensive. To go Explorer or Mustang you need the aluminum GT40 lower intake runs $650 and up. There is a cast iron version for about half that (I run one) but then you have all the other parts to add. With the T-body EFI just get an intake and mount it up......Self tuning so no need for a ECM tune or harness rework. You CAN reuse the stock 361W lower with an adaptor and Mustnag upper but it chokes off the W hat higher RPM's

As to HP.....The W is a nice step up for sure. The stock roller cam used in the explorer and roller block 351's has very nice low end torque. I reused the cam and rockers in my W build. I've since went to an aftermarket cam and added GT40P heads. Springs upgraded to match the cam.

Tim
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Dealing with firing order changes is a non-issue. If you can't move 4 spark plug wires you shouldn't be trying an engine swap.
Last I checked, AODs don't need any clutch linkage.

Oh, if you like you can use a 302 cam in a 351 and keep the old 302 firing order.
 
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