I have a 1979 Ford F-150 4X4. It has a 351M. I want to make do stuff to it to make it have more power. I need advice on what to do. Even if it means on takin it out and puttin in a big block.

 

You missed the correct section of this site just slightly. Try here for all your 351C, 351M, and 400 questions. Word of advice though....its not called the 351 modified. Its just a 351M. The M has not true meaning except to designate a difference to the 351C or 351W.

Here's the link 335 Series- 5.8/351M, 6.6/400, 351 Cleveland - Ford Truck Enthusiasts Forums

 

The 335 forums have tons of info.

Your 351M started life as a tall-deck version of the 351C, which was the 400 engine intro'd in '71. If you accept "big block" to be deck height over 10 inches, you have a big block. In 1975, Ford, seeking to drive everyone to madness, introduced yet another 351 size engine by destroking the 400 into the 351M.

From a recent post:

<TABLE class=tborder id=post6299709 cellSpacing=1 cellPadding=6 width="100%" align=center border=0 itxtvisited="1"><TBODY itxtvisited="1"><TR itxtvisited="1"><TD class=alt2 style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; PADDING-TOP: 0px" itxtvisited="1"><TABLE cellSpacing=6 cellPadding=0 width="100%" border=0 itxtvisited="1"><TBODY itxtvisited="1"><TR itxtvisited="1"><TD width="100%" itxtvisited="1"></TD><!--<td width="100%" style="padding-left:25px;"></td>--><TD vAlign=top noWrap itxtvisited="1">Join Date: Apr 2004
Posts: 5,040



</TD></TR></TBODY></TABLE><!-- / user info --></TD></TR><TR itxtvisited="1"><TD class=alt1 id=td_post_6299709 itxtvisited="1"><!-- message, attachments, sig --><!-- message --><TABLE width="100%" border=0 itxtvisited="1"><TBODY itxtvisited="1"><TR itxtvisited="1"><TD vAlign=top itxtvisited="1">BB/SB terms used in the heading of the engine forums here, so I guess it's not just a Chev term.

In the '60s, it was pretty easy to label engines SB/BB, as most mfgs (except Pontiac) had one of each. (289/390, 327/427, 273/413 for example)

By the time Ford introduced their FOURTH engine with a 4" x 3.5" bore and stroke, who could tell what was what?

Since the 351M & 400 share a block, it just adds to the head scratching.

Best to use the series & other (like 351M, C or W) to keep it straight.

One way to settle BB vs SB is deck height. Hot Rod mag says 10 inches makes a BB. Ooops, a 396 Chev is 9.8... so anything CLOSE to 10" counts. Some info here:

Deck Height and Compression Distance Data

Guess what engine has a deck height of 10.297.............

BTW, OP's question was timing. Try 6 degrees BTDC, and work out to maybe 10 and see how it runs.
</TD></TR></TBODY></TABLE><!-- / message --><!-- edit note --><HR style="COLOR: #d1d1e1" SIZE=1 itxtvisited="1">Last edited by 85e150six4mtod : 06-29-2008 at 10:11 PM. Reason: To confuse and anger more members...
<!-- / edit note --></TD></TR></TBODY></TABLE>


So, the easiest way to more power for you is a 400 crank, and then follow the proven mods to this engine which include:

--straight up cam timing, vs. factory retarded

--a better cam

--higher compression, 9.2-9.5, this means new pistons but you are buying those anyway with a rebuild

--research oiling mods

These alone wake it up quite a bit, going on to heads, manifolds, headers etc can put you into 400 horse territory.

Lots of info in the 335 forums, good luck.....

 

Thanks for the advice.

 

1 Question:
could i put a set of aluminum 351C Heads on this block?

 

Affirmative.