Posts: 9722
Joined: 2/9/2005 From: KY Status: offline
guys here are a few articles i found that i saved on my computer when i was doing 351w swap research
347 vs. 351 If you’re considering extra cubes, then chances are you’re wrestling with a fairly common dilemma: Do you build a 347 out of your 5.0 or step all the way up to a 351? Perhaps the following info will help you decide.
351W: Advantages •Strength: The 351W block is stronger than the production 5.0 by a long shot. Thicker walls and 3-inch main, and 2.311-inch rod journals (versus 2.248/2.123 for the 5.0) are contributing factors. • Taller Deck: The 351W features a deck height of 9.503 inches versus the 5.0’s 8.206 inches. This means a longer rod can be used for even more cubes—up to 435 with a production two-bolt block, and 454 cubes with a four-bolt FRPP block, according to George Klass at Coast High Performance. • Rod-to-Stroke Ratio: In stock configuration, the 351 has a better rod-to-stroke ratio than a 347 (1.70:1 for the 351W versus 1.58:1 for the 347) by virtue of its longer rods (5.956 versus 5.400 for the typical 347 rod). The 347 also features ½-inch head bolts instead of the 302 block’s 7/16-inch bolts. 351W: Disadvantages • Size: The 351W is 2.250 inches wider than a 302, necessitating a number of changes (at additional cost) to make the swap possible. Hood clearance can become an issue, and there will be less room to service the plugs. • Heavy Weight: As discussed in the Keep the Muscle, Lose the Fat sidebar, the 351W is beefier and is typically more than 100 pounds heavier than a 302-based engine. 347: Advantages • 302-based: The 347 is created when a 302 block is bored 0.030 and fitted with a 3.400 stroke crank and custom rods/pistons. This means a 347 has the extra cubes you desire, yet it can still use the same headers, manifolds, brackets, and so on as a stock 302. • Light Weight: The 302-based engine is more than 100 pounds lighter than the 351 in stock form, and it can be made downright feathery with a few aluminum components. 347: Disadvantages (and perceived disadvantages) • Limited Growth: While 347 ci is certainly a respectable number, it’s the practical displacement limit for a two-bolt-main production block. • Limited Strength: A two-bolt-main production block is typically capable of withstanding up to 600 hp, and that’s with a girdle, studded mains, and so on. Even a mildly built 347 with a supercharger can bust that figure. An R302 block will solve the problem, but there goes your budget. • Poor Rod-to-Stroke Ratio (perceived): There has been a lot of talk about the 347’s rod-to-stroke (R/S) ratio. Simply stated, the R/S ratio is the length of the connecting rod (center-to-center) versus stroke of the engine. A higher ratio means the piston stays at top dead center longer, promoting better combustion and, theoretically, more power. Compared to the 351W’s 1.70:1 R/S ratio, the typical 347’s R/S ratio of 1.58:1 doesn’t look good, but it’s actually better than a lot of other noted performance engines, including the 454 big-block Chevy (1.53:1) and 400 small-block Chevy (1.48:1). Even the legendary 428 CJ was only marginally better than a 347 at 1.63:1. Unless you’re building an engine to compete with Billy Glidden, R/S ratio really doesn’t add up to much in an otherwise well-built engine. Cost Factor The next thing you’d probably like to know is, which would be cheaper, a 347 or a 351W? As discussed, the 351W requires numerous extra parts to accomplish the swap, while the 347 doesn’t. However, depending on what 347 kit you purchase, the initial short-block may be more expensive than a 351W. Since we can’t know what combo you have planned, the best idea is to add up the cost of a 351W, factor in the extra parts, and then compare that to the cost of the 347, keeping in mind both engines can use the same heads. Our guess is that the 347 will probably be less, but depending on how serious you plan to get, a 351W swap could be equal to, or less than, the cost of a truly serious 347.
i found it on the 50mustang and super fords website i believe
< Message edited by Jasperstang308 -- 11/19/2007 9:52:55 AM >
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87 notch a notch above the rest crossed over to the dark side +1 arent allowed in 50 tech sections
Yea a 347 would have been nice but my 351w was just so damn cheap. A stock swap from a 302 to a 351w dropped me 2.1 seconds in the QT for around a grand. Cant get any better then that.
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1983 Mustang GT, 357w, Edelbrock Top end Kit, 650 double pump, Magnum pro rockers, catless MAC full exhaust, 3:73's (8.8) with MT ET streets. B&M Short throw.
i have a 95 gt w a 302 but this summer i was planning a 351 swap and was wonderin a few things. could i use my stock eec and add a piggyback programer? where would i find a oil pan that will work? and will my stock t5 tranny hold up against the extra power/torque? its not goin to be a real hot motor bc its still a daily driver, itll still be efi w a healthy cam, gt40 heads and headers. who has headers for this swap? I love the previous 347vs351 info and im lookin forward to any info you can help me with.
I have a 1982 Mercury Capri RS that i am currently in the act of restoring for summer. it currently has 302 that is in excellant shape( i have taken it apart myself and everything is clean, also i have another 82' 302 out of a GT my dad used to own.) but i wanted to swap in a and 82' or 83' 351W that was in an older pickup with only about 40000 miles on it. And i was just wondering besides a new oil pan what i need to do get it in there. Im only a junior in high school so money is tight but my dad has every tool imaginable and a ton of parts from numerous ford mustangs and such. i also was wondering what heads, intake, cam, and headers would be good for this setup. It will be driven daily but will see time at Route 66 raceway on weekends. Any help would be extremely helpful so i can do it right. Also, may be able to have access to a supercharger. And i was just wondering i would have to do to get that on there.
< Message edited by No Truck Like Ford -- 2/28/2008 4:11:43 PM >
hey i know this is a mustang website but sum1 mite be able to help me (hopefully)!!!!! i have an 85 full size bronco w a windsor and for sum reason every time i connect the "brain box" the voltage on the battery drops drastically and continues to fall at ab a tenth a volt per second. i checked the voltage regulator and i got a new box for it. the readout was ab 11.54 volts (it ran dead and never got fully recharged) but when i hookup the box it drops to ab 4 volts and continues to fall?!!! i dont know whats goin on, i thought a relay mounted by the brake booster was stickin but even w it unhooked it still falls. any1 please let me know if you know sumthin. thanks for bearin w me on this non mustang related ( but ford windsor ) question.
hey thanks for the site jasper! hey on my car the dome lights dont work. theyre ran throuth the alarm control box in the trunk, i swapped in my girlfriends outta her stang and they worked. does that box have to be out of a stang or could i just go to the junk yard and get one outta nething, say like a vic or sumthin, and if i do should i find one w the remotes w it or could i just give the dealership the num of the box and have them order sum? is it true that the 5.0 explorers have iron gt40 heads and a cobra style intake? thats what ive read on another site.
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Some things to consider with your 351 swap - 
