351 in a FOX
01-01-2007, 01:21 PM
#1
2nd Gear Member
Thread Starter
Join Date: Mar 2006
Location: Warwick, RI
Posts: 289
351 in a FOX
Hey guys, I'm starting to piece together the parts for my next build. I'm sure you've seen afew of my earlier posts, but I'm going to be building a 351W, so therefore I'm going to be needing some extra parts that I wouldnt be necessary if I were staying true to the course of the 302 in a Fox. So here are afew questions for all you guys to answer. Can I use my BBK longtubes and BBK H pipe on my 351?In reguards to that, The heads i'm putting on the motor are from my 302. I will need a 157 tooth 28 OZ Flywheel also, correct? The motors out of a 80's 2500 Van. Next, I notice the pulley system is much different than whats on my 302. Is there a way to convert it to a single Serpintine? Am I going to need a new hood due to the taller deck height? Will I need a new oilpan to clear the k memeber in my 86 GT? ANY other information you guys can provide about this build would be greatly aprecaited.Or if there are any sources with information about this. I'm trying to do all my homework now, so I dont run into any issues when the build begins. Thank you all for the help, and hope everyone was safe and had fun last night.
01-01-2007, 01:43 PM
#2
2nd Gear Member
Join Date: Dec 2006
Location: Feasterville, Pa
Posts: 228
RE: 351 in a FOX
no your current headers and hpipe wont fit. bbk makes long tubes w/matching hpipe specifically for the 351-in-a-fox conversion. check march's website about he pullies. i think they have a kit for the 351 serpentine. as far as the hood issue. your prob. going to need a @ least a 1.5" cowl hood to clear(thats the easiest way. you can get real trick using lowered motor mounts but that seems to be too complicated to me). milodon also makes an oil pan for the 351-in-a-fox conversion.
01-01-2007, 03:48 PM
#5
4th Gear Member
Join Date: Feb 2006
Location: Seattle, WA
Posts: 1,375
RE: 351 in a FOX
Double check with BBK before buying a new midpipe. If they designed the setup properly, the swap headers should bolt up to all of their midpipes. Depends on how they designed it though.
I am guessing that the 86 is still carb'd, and that you plan on staying carb'd with the 351w?
If that is the case then you should be able to clear the stock hood, if you are careful about picking a manifold, carb, filter combo.
You should be able to run the belt system from the 302 on the 351w. If you want serpentine, then just find a junk yard car to source everything from...
There is one bracket you will need to buy though, the A/C & P/S bracket. This is available from Ford through many retailers. Part numbers are on my site...
I have a fair amount of info on my site, but it is focused on doing the conversion with EFI.
Most of it should be the same though.
Updated 12-26-06
http://www.freewebs.com/vristang/fox351wswapfaq.htm[/i]
302 to 351W Swap in a Fox Body Mustang
VRISTANG[/i]
Note:[/i][/b]
This FAQ was written for converting a T-5 5.0 efi Mustang to a T-5 351w efi Mustang. The conversion will be slightly different if starting with a 2.3l or carbureted Mustang OR converting to a carbureted 351w. Converting transmissions is beyond the scope of this document.[/i][/b]
Background Info-
The major disadvantage of the 302 is its lack of strength at high power levels. Most will agree that at ~500hp the factory 302 block will try to split in half. For many the solution to this is an aftermarket 302 block, which can be expensive.
Another alternative is to swap in a 351w block. The 351w is supported by the aftermarket nearly as well as the 302, but can handle much more power than the 302. Some common safe power numbers given for the 351w are usually in the 600-700hp range. There are 2 basic production blocks available; the 69-70 blocks had a deck height of 9.480â€, and the 71 up blocks had a deck height of 9.503.†This is compared to the 302 deck height of 8.200â€.
351w Casting Numbers
The casting numbers are on the passenger side near the starter location. You will have to turn the block upside down, or use a mirror to see them.
The year will be designated by the first 2 digits of the casting number.
The first digit is the decade and will be a letter. C=1960's, D=1970's, E=1980's, and so on. The second digit will be a number andspecifies the year of the decade. Some examples follow:
D1=1971
E9=1989
F4=1994
For more info on how to identify various Ford engine blocks check out the following link…
http://www.fordification.com/engineID.htm
Getting Into the Nitty-Gritty
The 351w Engine Block -
69-70[/b] - High Nickel content and thicker main webs (These are the only Production Ford 9.480" Deck Height 351w blocks)
71-74[/b] - Reduced Nickel content thinner main webs (71-up had 9.503" Deck Height)
75-91[/b] - Reduced main web thickness
92-On[/b] -Lifter Bores were lengthened to accept roller lifters
There were some 351w Mexican blocks as well. The early versions of which are desirable due to their beefier castings and higher nickel contents. A Mexican block can be identified by the useless looking ***** cast into the block on either side of the timing cover, and an “Hencho en Mexico†cast into the lifter valley. Mexican blocks were supposedly used on some US vehicles, but they are a fairly rare find.
Camshaft and Lifters-
The specs of the cam will depend mostly on what your goals are for the motor. Cam spec selection is way beyond the scope of this FAQ. What you want to watch out for is selecting the correct base circle for the lifter combination and using the stock 302 HO firing order (since you are most likely reusing the stock 302computer).
69-91 351w blocks -
Roller Lifter Option 1) Standard Base Circle Cam / Aftermarket Linked Bar Hydraulic Roller Lifters
Roller Lifter Option 2) Small Base Circle Cam / 302 HO Roller Lifters
92 & Later 351w blocks -
The Standard Base Circle Cam can be used with 302 HO Roller Lifters.
A Small Base Circle Cam is not needed in these blocks.
(The 92 and later "roller" blocks will have a F4TE casted into the block near the starter)
If using solid lifters (either flat tappet or roller) then a standard base circle cam can be used on any year 351w block.
If in doubt,ask the company you plan on purchasing the cam from (or better yet a reputable engine builder) what would be appropriate for your application. They will need to know what year the block is and what lifters you plan on running. Additionally it may be helpful to have your rocker ratio available, and what piston you will be using if not stock.
NOTE: Small Base Circle Camsare known to be less than ideal, as they are weaker. There are not as many cam profiles available fortheSmall Base Circle Cams, so yourOffthe Shelf Cam selection will be severely limited. If possible, it is recommended to avoid the Small Base Circle Cams.
Firing Orders-
Early 289 & 3021-5-4-2-6-3-7-8
302HO &351w 1-3-7-2-6-5-4-8 (this is all 83-93 Mustangs, and all 5.0 Explorers)
Pushrods-
Again, there are far too many options available to cover here. Check with the cam manufacturer on what length pushrod you will need. Or even better, you can use a pushrod length checker and measure them yourself.
Roller Lifters-
The stock 302 lifters can be swapped over to the 351w(see the cam discussion above)with a little machining/grinding and a reduced base circle cam.
First the spider will require 2 holes to be drilled in the main valley. These holes will be drilled over the cam bearings, so great care should be taken not to damage the camshaft or bearings. Risk can be minimized by removing the camshaft, and drilling the holes before the cam bearings are installed. Some grindingmay need to be done to allow the factory 302 dogbones to sit flush on the 351w block as well. A Dremel is adequate to get the job done. Be patient and work slow; it is easier to remove material than put it back. Of course it would be best to do this work before having the block cleaned and prepped for assembly. Ford Hydraulic Roller lifter (for both the 302 and 351w) part number is M-6500-302.
If all of this does not sound appealing to you then maybe some of the aftermarket roller lifters will be a better option. These tend to be fairly expensive however. Look for lifter pairs that have a link bar, connecting each pair of lifters.
Rocker Arms-
This will depend on the heads you select. All of the same rules that apply to selecting rockers for a 302 still apply to the 351w. Options to consider are Pedestal vs. Stud Mount, Roller vs. Non-Roller, and Brand.
Engine Mounts-
Stock 5.0 mounts will bolt up to the 351w. Aftermarket alternatives include solid mounts and polyurethane mounts. Convertible Engine mounts are rumored to be stronger & shorter. Another alternative is a set of lowering engine mounts from either Year One, Moroso, or HP Motorsports (HPM). These are solid and lower the motor ~¾â€. Lowering engine mounts are useful for gaining hood clearance, but will also reduce clearance between the oil pan
I am guessing that the 86 is still carb'd, and that you plan on staying carb'd with the 351w?
If that is the case then you should be able to clear the stock hood, if you are careful about picking a manifold, carb, filter combo.
You should be able to run the belt system from the 302 on the 351w. If you want serpentine, then just find a junk yard car to source everything from...
There is one bracket you will need to buy though, the A/C & P/S bracket. This is available from Ford through many retailers. Part numbers are on my site...
I have a fair amount of info on my site, but it is focused on doing the conversion with EFI.
Most of it should be the same though.
Updated 12-26-06
http://www.freewebs.com/vristang/fox351wswapfaq.htm[/i]
302 to 351W Swap in a Fox Body Mustang
VRISTANG[/i]
Note:[/i][/b]
This FAQ was written for converting a T-5 5.0 efi Mustang to a T-5 351w efi Mustang. The conversion will be slightly different if starting with a 2.3l or carbureted Mustang OR converting to a carbureted 351w. Converting transmissions is beyond the scope of this document.[/i][/b]
Background Info-
The major disadvantage of the 302 is its lack of strength at high power levels. Most will agree that at ~500hp the factory 302 block will try to split in half. For many the solution to this is an aftermarket 302 block, which can be expensive.
Another alternative is to swap in a 351w block. The 351w is supported by the aftermarket nearly as well as the 302, but can handle much more power than the 302. Some common safe power numbers given for the 351w are usually in the 600-700hp range. There are 2 basic production blocks available; the 69-70 blocks had a deck height of 9.480â€, and the 71 up blocks had a deck height of 9.503.†This is compared to the 302 deck height of 8.200â€.
351w Casting Numbers
The casting numbers are on the passenger side near the starter location. You will have to turn the block upside down, or use a mirror to see them.
The year will be designated by the first 2 digits of the casting number.
The first digit is the decade and will be a letter. C=1960's, D=1970's, E=1980's, and so on. The second digit will be a number andspecifies the year of the decade. Some examples follow:
D1=1971
E9=1989
F4=1994
For more info on how to identify various Ford engine blocks check out the following link…
http://www.fordification.com/engineID.htm
Getting Into the Nitty-Gritty
The 351w Engine Block -
69-70[/b] - High Nickel content and thicker main webs (These are the only Production Ford 9.480" Deck Height 351w blocks)
71-74[/b] - Reduced Nickel content thinner main webs (71-up had 9.503" Deck Height)
75-91[/b] - Reduced main web thickness
92-On[/b] -Lifter Bores were lengthened to accept roller lifters
There were some 351w Mexican blocks as well. The early versions of which are desirable due to their beefier castings and higher nickel contents. A Mexican block can be identified by the useless looking ***** cast into the block on either side of the timing cover, and an “Hencho en Mexico†cast into the lifter valley. Mexican blocks were supposedly used on some US vehicles, but they are a fairly rare find.
Camshaft and Lifters-
The specs of the cam will depend mostly on what your goals are for the motor. Cam spec selection is way beyond the scope of this FAQ. What you want to watch out for is selecting the correct base circle for the lifter combination and using the stock 302 HO firing order (since you are most likely reusing the stock 302computer).
69-91 351w blocks -
Roller Lifter Option 1) Standard Base Circle Cam / Aftermarket Linked Bar Hydraulic Roller Lifters
Roller Lifter Option 2) Small Base Circle Cam / 302 HO Roller Lifters
92 & Later 351w blocks -
The Standard Base Circle Cam can be used with 302 HO Roller Lifters.
A Small Base Circle Cam is not needed in these blocks.
(The 92 and later "roller" blocks will have a F4TE casted into the block near the starter)
If using solid lifters (either flat tappet or roller) then a standard base circle cam can be used on any year 351w block.
If in doubt,ask the company you plan on purchasing the cam from (or better yet a reputable engine builder) what would be appropriate for your application. They will need to know what year the block is and what lifters you plan on running. Additionally it may be helpful to have your rocker ratio available, and what piston you will be using if not stock.
NOTE: Small Base Circle Camsare known to be less than ideal, as they are weaker. There are not as many cam profiles available fortheSmall Base Circle Cams, so yourOffthe Shelf Cam selection will be severely limited. If possible, it is recommended to avoid the Small Base Circle Cams.
Firing Orders-
Early 289 & 3021-5-4-2-6-3-7-8
302HO &351w 1-3-7-2-6-5-4-8 (this is all 83-93 Mustangs, and all 5.0 Explorers)
Pushrods-
Again, there are far too many options available to cover here. Check with the cam manufacturer on what length pushrod you will need. Or even better, you can use a pushrod length checker and measure them yourself.
Roller Lifters-
The stock 302 lifters can be swapped over to the 351w(see the cam discussion above)with a little machining/grinding and a reduced base circle cam.
First the spider will require 2 holes to be drilled in the main valley. These holes will be drilled over the cam bearings, so great care should be taken not to damage the camshaft or bearings. Risk can be minimized by removing the camshaft, and drilling the holes before the cam bearings are installed. Some grindingmay need to be done to allow the factory 302 dogbones to sit flush on the 351w block as well. A Dremel is adequate to get the job done. Be patient and work slow; it is easier to remove material than put it back. Of course it would be best to do this work before having the block cleaned and prepped for assembly. Ford Hydraulic Roller lifter (for both the 302 and 351w) part number is M-6500-302.
If all of this does not sound appealing to you then maybe some of the aftermarket roller lifters will be a better option. These tend to be fairly expensive however. Look for lifter pairs that have a link bar, connecting each pair of lifters.
Rocker Arms-
This will depend on the heads you select. All of the same rules that apply to selecting rockers for a 302 still apply to the 351w. Options to consider are Pedestal vs. Stud Mount, Roller vs. Non-Roller, and Brand.
Engine Mounts-
Stock 5.0 mounts will bolt up to the 351w. Aftermarket alternatives include solid mounts and polyurethane mounts. Convertible Engine mounts are rumored to be stronger & shorter. Another alternative is a set of lowering engine mounts from either Year One, Moroso, or HP Motorsports (HPM). These are solid and lower the motor ~¾â€. Lowering engine mounts are useful for gaining hood clearance, but will also reduce clearance between the oil pan
01-01-2007, 05:30 PM
#7
4th Gear Member
Join Date: Feb 2006
Location: Seattle, WA
Posts: 1,375
RE: 351 in a FOX
ORIGINAL: 89Ford
86 mustangs were efi and the 351w is a small block...just wanted to clear up the mistakes.....
and Hurricane how much did you get the engine for?
86 mustangs were efi and the 351w is a small block...just wanted to clear up the mistakes.....
and Hurricane how much did you get the engine for?
A MAF conversion should be considered, as the SD computer will have problems with the increase in displacement.
Did I say the 351w was NOTa small block?
jason
01-01-2007, 06:03 PM
#9
4th Gear Member
Join Date: Feb 2006
Location: South Jersey
Posts: 1,250
RE: 351 in a FOX
ORIGINAL: vristang
I stand corrected, the 86 was SD EFI.
A MAF conversion should be considered, as the SD computer will have problems with the increase in displacement.
Did I say the 351w was NOTa small block?
jason
ORIGINAL: 89Ford
86 mustangs were efi and the 351w is a small block...just wanted to clear up the mistakes.....
and Hurricane how much did you get the engine for?
86 mustangs were efi and the 351w is a small block...just wanted to clear up the mistakes.....
and Hurricane how much did you get the engine for?
A MAF conversion should be considered, as the SD computer will have problems with the increase in displacement.
Did I say the 351w was NOTa small block?
jason
01-01-2007, 07:24 PM
#10
4th Gear Member
Join Date: Feb 2006
Location: Seattle, WA
Posts: 1,375
RE: 351 in a FOX
ORIGINAL: 89Ford
my bad jason, i was referring to the other guy, I know you know about 351w, In fact Ive read you write up on the swap several time now, I cant wait to have a car comparable to yours...you are right about the MAF its going to be needed if he keeps it efi
ORIGINAL: vristang
I stand corrected, the 86 was SD EFI.
A MAF conversion should be considered, as the SD computer will have problems with the increase in displacement.
Did I say the 351w was NOTa small block?
jason
ORIGINAL: 89Ford
86 mustangs were efi and the 351w is a small block...just wanted to clear up the mistakes.....
and Hurricane how much did you get the engine for?
86 mustangs were efi and the 351w is a small block...just wanted to clear up the mistakes.....
and Hurricane how much did you get the engine for?
A MAF conversion should be considered, as the SD computer will have problems with the increase in displacement.
Did I say the 351w was NOTa small block?
jason
I just wanted to make sure that if I had screwed something up, I at least get it corrected.
Glad you liked the writeup, hope it helps.
