302 to 351W swap

djpritchard · #1 (**permalink**) 07-27-2005, 03:23 AM

I had a 302 and when digging in to it, it needs major work. Have an opportunity to pick up a 351W, but I noticed the motor mounts are different. THe 302 mounts only have two bolts, where the 351W has three. My question is - will the mounts for the 351W fit the crossmember that the 302 sat on. I was under the impression the 302 and 351W had the same block - and the only difference was the cylinders were 1-1/2" longer?

THanks

Dave

351-EM · #2 (**permalink**) 07-27-2005, 03:46 AM

Dave,

There should be no difference between the motor mounts or mounting points for the 302 vice 351W. I used 67 289 motor mounts for my 351W install in my Cobra. As you mentioned in your post, the only difference is in the deck height. Other than that it should be a relatively pain free swap. As far as the two bolts versus the three bolts, are you talking about the motor mount itself, or where it bolts to the block. Either way, you threw me for a loop on that one. What type of chassis is it going into? (Unique, Contemporary, Shell Valley etc....). Hope it goes well.

Chris

djpritchard · #3 (**permalink**) 07-27-2005, 04:33 AM

351-EM - it's the bolts to the motor where the 351 has three bolts, versus the two bolts per mount on the 302.

Thanks

Dave

351-EM · #4 (**permalink**) 07-27-2005, 11:41 AM

Dave,

I can honestly say that I have never seen a three bolt motor mount on a ford engine. All of my experiences have been with small and big blocks, but I 've never seen that before. Any way to get pictures, as that may give me a better idea how to respond or offer assistance.

Chris

Daniel Jones · #5 (**permalink**) 07-27-2005, 01:29 PM

3 holes in a triangular pattern isounds like a 351M or a 400. Did you compare the bellhousing pattern. If those don't match, it's not a 351W. Does it have the thermostat in the block or intake?

Dan Jones

djpritchard · #6 (**permalink**) 07-27-2005, 01:45 PM

Dan - I'll check when I get home and respond to your thermostat question. As I'm getting an education in this venture - how does teh 351M compare to the 351C? Also how many valve cover bolts would teh 351M have?

Thanks

Dave

Daniel Jones · #7 (**permalink**) 07-28-2005, 10:28 AM

> Dan - I'll check when I get home and respond to your thermostat question. As
> I'm getting an education in this venture - how does teh 351M compare to the
> 351C?

The 351M is a de-stroked 400 and is larger and heavier than a 351C.
The 351M/400 blocks are 1" taller deck versions of the 351C with
larger mains and 429/460 bellhousing patterns (there were some 400
blocks that were cast with the small block bellhousing pattern but
they are relatively rare). They had very low compression, a wimpy
cam, 2 barrel carb, single exhaust and were total dogs in stock early
emissions-era form. Of course, there's no reason they have to stay
that way. The potential is there since they are essentially just
351 Clevelands with (usually) thicker walls, a half inch longer stroke
(for the 400), an inch taller deck (10.297" vs 9.206") and nice long
rods (6.580" vs 5.778"). Slap a set of 4V heads on top with a Blue
Thunder high rise dual plane, a decent cam and compression and it'll
be a completely different engine. The 400 cranks can be offset ground
for more displacement. I know of one built for a truck that is 434
cubes and another that was built for a Pantera that is 438 cubes.
Might not be the best fit for your Cobra though.

> Also how many valve cover bolts would teh 351M have?

8, same as a 351C.

Dan Jones

cobrashoch · #8 (**permalink**) 08-06-2005, 08:52 PM

Dan - I didn't know there were 400/mod blocks with small bolt pattern trannys. (in trucks?) I'll have to remember that. Were they 2 bolt or 4 bolt mains? All of the modified engines I've found in junk yards had 2V or 4V Cleveland open chamber heads, perfect for blower heads.
cobrashock

Daniel Jones · #9 (**permalink**) 08-08-2005, 01:56 PM

> Dan - I didn't know there were 400/mod blocks with small bolt pattern
> trannys. (in trucks?)

I've only seen them in passenger cars. They are sometimes referred to
as FMX blocks and are fairly rare. Here's a picture of a rusty one:

http://www.bacomatic.org/~dw/fengpix1/odd400.jpg

Notice the skeletal outline of the big block pattern.

> Were they 2 bolt or 4 bolt mains?

2 bolt mains but I think Pro Gram Engineering makes 4 bolt main caps
for them. One of the PAntera guys did one with Webers and a 4 bolt main
conversion.

> All of the modified engines I've found in junk yards had 2V or 4V
> Cleveland open chamber heads, perfect for blower heads.

The stock 351M/400 heads are similar to 351C-2V but have inferior
exhaust ports and some have a water filled passage that can't be ported
away.

Dan Jones

cobrashoch · #10 (**permalink**) 08-08-2005, 05:05 PM

Dan - thanks. Seems there's more ways than one to skin the Pantera cat.
cobrashock

Daniel Jones · #11 (**permalink**) 08-09-2005, 10:55 AM

> Dan - thanks. Seems there's more ways than one to skin the Pantera cat.

Yes there are. I came up with one of the 400 blocks with SBF bellhousing
pattern a while back and was thinking about doing a stroker for the Pantera
using that block, a set of A3 high port heads and a matching A331 intake
w/spacers. We were going to offset grind the 400 crank for 434 cubes. Then
I came up with one of the XE NASCAR 351C blocks and decided to just stroke
it instead. I ended up selling that to Jon Kaase for the Engine Masters
Competition and bought a used Fontana aluminum block instead. With the
C302B heads, aluminum flywheel, stroker crank, mini starter etc. it should
weigh in a little over 400 lbs and be 407 cubes (4.1" bore by 3.85" stroke).
I'm hoping the engine will be done in the next month.

One of the Pantera guys is doing a 400 stroker with CHI heads:

http://www.tmeyerinc.com/400stroker.html

He's using a custom bellhousing with the standard 400 block:

http://www.rc-tech.net/per/bell.jpg

A number of guys have also fitted Ford Motorsport 460 strokers.

Dan Jones