Big Block or small block?
Thread Starter
|
Freshman User
Joined: Oct 2008
Posts: 45
Likes: 0
From: Crocker Mo
Big Block or small block?
Can someone answer me once and for all is the 400 a BB or SB ? Its the original motor in my 1978 F150 4X4. Some people says its a small block I think its a Big Block which is it? Thanks
Posting Guru
Joined: Nov 2007
Posts: 1,305
Likes: 2
From: Montgomery, IL
it is kind of a weird engine. I would call it a small block, along with its sister engine the 351m, but they both have the same trans bolt pattern as a 460 big block, meaning you can pull a 400 out and bolt a 460 to the same trans.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Trending Topics
Posting Guru
Joined: Jul 2006
Posts: 1,354
Likes: 1
From: America
call it whatever sounds better. if youre racing call it a small block. If you win, it was a small block beating whatever else you raced, if you lose it doesnt matter because its just a little ol smallblock.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Super Moderator
Joined: Apr 2004
Posts: 34,475
Likes: 2,800
If you accept a deck height of 10" + as big block, it's a big block. However, it has small block bore spacing. The 351c is a small block. Note the deck on a 400 is taller than an FE.
By the time the 400, and certainly the 351M, was introduced, Ford had many engine series in use, so BB/SB gets you nowhere.
In the mid '60s when the SB/BB got it's start, probably with Chev, Ford was similarly arranged with the 260/289/302 series vs. the FE series. It was easy to figure using the terms. Now, not so much--you need to know the series. Ford makes it tough--imagine 4 different engines with a 4" bore and 3.5" stroke, within a few model years of each other, and for some years, 2 in production at the same time. Huh?
By the time the 400, and certainly the 351M, was introduced, Ford had many engine series in use, so BB/SB gets you nowhere.
In the mid '60s when the SB/BB got it's start, probably with Chev, Ford was similarly arranged with the 260/289/302 series vs. the FE series. It was easy to figure using the terms. Now, not so much--you need to know the series. Ford makes it tough--imagine 4 different engines with a 4" bore and 3.5" stroke, within a few model years of each other, and for some years, 2 in production at the same time. Huh?
I'll have the Roast Duck
Joined: Jul 2002
Posts: 9,622
Likes: 108
From: Northshore, MN
lol.
Lower half of the engine is a "small block" as it's the same as a 302, except motor mount bolt holes. Heads are Cleveland size, and 99 out of 100 blocks have the 460 size bell pattern.
Lower half of the engine is a "small block" as it's the same as a 302, except motor mount bolt holes. Heads are Cleveland size, and 99 out of 100 blocks have the 460 size bell pattern.
Super Moderator
Joined: Apr 2004
Posts: 34,475
Likes: 2,800
Bore spacing, and cylinder to block bolt patterns are the same. Heads are similar, but are not the same parts.
Source: Found at the top of the "Small Block V8...." forums:
Kelly hotrod - Ford Engines Page 1
They do share the bell pattern with the 385, except as you note, some 1973 castings have the SBF pattern.
I'll have the Roast Duck
Joined: Jul 2002
Posts: 9,622
Likes: 108
From: Northshore, MN
That's why I said lower half. 
Dimensionally the 400 fit's the same frame perches as the 302 and other 351's. Even the bosses cast in my 400 fit the 302 motor mounts as it sits in my Fox Tbird.
Dimensionally the 400 fit's the same frame perches as the 302 and other 351's. Even the bosses cast in my 400 fit the 302 motor mounts as it sits in my Fox Tbird.
