WHAT IS THE BEST 351 BLOCK TO USE?

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laford1986

New Member

Feb 8, 2006

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Jun 25, 2006

#1

• Jun 25, 2006

• #1

I am planning the build up if a stroker 351W. I need some information on making a decision on what is the best PRODUCTION block to use, ie. what year of vehicle, model, etc. thanks in advance

 

R

R2D2

Jun 25, 2006

#2

• Jun 25, 2006

• #2

there are 2 different deck heights production blocks, the first being 69-70 models were 9.48 and the 71 and up are 9.503. Find an early 71-75 block, look in dump trucks, buses, vans etc.

 

vristang

15 Year Member

Mar 31, 2005

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Jun 25, 2006

#3

• Jun 25, 2006

• #3

^^^Correct

Here is some more detail from my swap FAQ

http://www.freewebs.com/vristang/fox351wswapfaq.htm

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.
Another alternative is to swap in a 351w block. There are 2 production blocks available; the 69-70 blocks had a deck height of 9.480”, and the 71 up blocks had a deck height of 9.503.” This is compared to the 302 deck height of 8.200” The 69-70 blocks also had thicker main webs and higher nickel content, making them significantly stronger. From 70 to 74 the 351w maintained the higher nickel content, but lost some of the material in the main webs. Another small reduction in the main web thickness occurred in 75, along with another reduction in Nickel content (supposedly), but after that the block remained basically unchanged until it ended production. From 1994 on, all 351w blocks were equipped with roller cams/lifters. ​

 

vristang

15 Year Member

Mar 31, 2005

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Jun 25, 2006

#4

• Jun 25, 2006

• #4

The 351w can also be found in pickup trucks and some larger mid 70s sedans.


jason

 

fidstang

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Jul 19, 2005

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South Lansing

Jun 25, 2006

#5

• Jun 25, 2006

• #5

Has anyone ever machined a 351 to a deck height of a 302? Yeah, I know what your thinking why! Just a curious question.

 

R

R2D2

Jun 25, 2006

#6

• Jun 25, 2006

• #6

fidstang said:

Has anyone ever machined a 351 to a deck height of a 302? Yeah, I know what your thinking why! Just a curious question.

Click to expand...

100% impossible

 

fidstang

New Member

Jul 19, 2005

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South Lansing

Jun 25, 2006

#7

• Jun 25, 2006

• #7

That's what I thought. Has anyone ever figured out the real reason why the Mexican 302 blocks are stronger then the north american ones?

 

R

R2D2

Jun 26, 2006

#8

• Jun 26, 2006

• #8

fidstang said:

That's what I thought. Has anyone ever figured out the real reason why the Mexican 302 blocks are stronger then the north american ones?

Click to expand...

ya a quick visual reveals all, its not a real mystery why.

 

NosPony

New Member

Apr 2, 2004

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Canton, Il

Jun 26, 2006

#9

• Jun 26, 2006

• #9

they have a higher nickel content that makes them stronger.

 

R

R2D2

Jun 26, 2006

#10

• Jun 26, 2006

• #10

NosPony said:

they have a higher nickel content that makes them stronger.

Click to expand...

look at the main webbing, nothing to do with nickel content

 

352Ford2

New Member

Oct 12, 2005

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Seattle,WA

Jun 26, 2006

#11

• Jun 26, 2006

• #11

vristangFrom 1994 on said:

[/COLOR][/LEFT]

Click to expand...

not all, only H coded trucks/broncos

 

vristang

15 Year Member

Mar 31, 2005

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Jun 26, 2006

#12

• Jun 26, 2006

• #12

352Ford2 said:

not all, only H coded trucks/broncos

Click to expand...

I appreciate you bringing this up.
I would like to fix any errors you or anyone else finds in something I have written.

Can you provide more detail.

How to identify these blocks?
More detailed info on the trucks/broncos?
Were there even any cars that used the 351 in that time frame?
Do you have any links that discuss this?

I appreciate the contribution of knowledge

jason

 

D

DocZG

New Member

Jun 7, 2006

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San Antonio, Texas

Jun 26, 2006

#13

• Jun 26, 2006

• #13

I would also look into 351 Marine blocks. I have a 74 marine 351 and the machinest said he has never seen that much beef in a production 351. You can still use all the automotive 351 parts. If you can score the whole short block it would easily be good for 450hp with good bolts. I have heard that the older Marine 351's is good for about 750fwhp.... just what i heard

The Mexican blocks do have more nickel and are a stronger casting.

 

R

R2D2

Jun 26, 2006

#14

• Jun 26, 2006

• #14

no difference in maring blocks and auto blocks, been a scam to make more money from boat owners for decades, ford, chevy and mopar never had a different casting for the marine industry. The comment your machinist made was because it was the early block with the thicker main webbing

 

8

86bluecobra

Advanced Member

Dec 20, 2004

4,265

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69

B.C. Canada

Jun 26, 2006

#15

• Jun 26, 2006

• #15

yes i agree. marine engines are always the best of the automotive blocks. 440 marine engines for mopars for intance were 67 hp blocks. one of the strongest blocks in the 440's. i have a 72 windsor block and its right in the middle of the high nickel content blocks you want to look for. it has worked for my car for the past 5 years.

 

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mtbdoc

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Nov 2, 2003

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Jun 26, 2006

#16

• Jun 26, 2006

• #16

I'm having a 408 built by McAllister Brothers using a 69 block...and it will have a D2 Procharger feeding it. The car will be more cruise and show than all-out drag [although it will get a few runs...before being thrown off the track!] so I didn't go with a Dart block. Tracy believes we will be okay at 750-800hp [flywheel]...just hope the 40 y/o car is!

 

pb_paulie_b

Founding Member

May 19, 2001

894

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Chaptico, Maryland

Jun 26, 2006

#17

• Jun 26, 2006

• #17

The 69' block is the strongest stock 351w block. High nickle content and thicker main webbing. It is also flat at the top of the main webbing. This make it possible to go with 4 bolt mains.
View attachment 460124

 

352Ford2

New Member

Oct 12, 2005

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Seattle,WA

Jun 27, 2006

#18

• Jun 27, 2006

• #18

according to my speed pro book, the only roller 351 w's from the factory are some 1994-1997 light duty trucks (that includes suvs) that have the letter "H" in the VIN number for an engine code. yes suposedidly their are H coded trucks that have flat tappets too.

other than pulling the intake manifold I don't don;t of a way to check, but I am willing to bet engine block casting numbers would tell you (they have to be cast diffrent with bosses and deeper lifter bores.

vristang said:

I appreciate you bringing this up.
I would like to fix any errors you or anyone else finds in something I have written.

Can you provide more detail.

How to identify these blocks?
More detailed info on the trucks/broncos?
Were there even any cars that used the 351 in that time frame?
Do you have any links that discuss this?

I appreciate the contribution of knowledge

jason

Click to expand...

 

vristang

15 Year Member

Mar 31, 2005

4,933

101

124

Seattle

Jun 27, 2006

#19

• Jun 27, 2006

• #19

Thanks for coming back with that follow up info.

Does anyone have a pic of the lifter valley of a factory roller 351w?

I am doubtful that the casting was actually changed. If it was I would think that even the non-roller blocks would have the bosses for the roller gear. It would be more expensive to have 2 different engine blocks in production.

Interesting stuff,
jason

 

V

v8only

Active Member

Jul 3, 2003

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Jun 27, 2006

#20

• Jun 27, 2006

• #20

in all practicality, the later blocks are obviously easier to come by, and that's the block I'd go with. then again, I'd be lucky to get anywhere near 500 horse on my budget.

fyi, all 94+ 5.8 blocks were equipped to have a roller cam, although most blocks still came flat tappet. Grab a 94+ block, and that roller cam will go right in.