SN95 351W Swap

331_mustang

New Member
Aug 1, 2005
21
0
1
Gentlmen, I'm considering a 392 swap to replace the 331 in my '94 mustang. Has anyone had experience (succesful or otherwise) with a 351W swap in this body sytle? I'm aware of the R model Cobra and Saleens having a 351W in them, but I'm more interested in hearing from someone whose been through it first hand. I'd like to know about any problems that you ran into, a few specifics on parts (such as the brand of headers you used), and if I could get a couple of photo's for reference from you. Let me know if you can help out. Thanks!
 
  • Sponsors (?)


Check out my website in my sig for pics.

It seemed like a very easy swap to me. You will need a different intake, 351 swap headers, a 351 distributor, a different oil pan, and a different belt. Everything else should bolt up. The timing cover, water pump, and front accessories can all be re-used. Oh yeah, 351's use 1/2" head studs, so you may need to open up the holes in your heads to accept 1/2" studs. The AFR 225's, and I think the 205's, do not require drilling to fit 1/2" studs.

If you can afford the Kooks headers, get them!! They are individual tubes which make them very easy to install. www.kookscustomheaders.com

I also recommend a high-tourqe starter before you put everything back together. I got the Powermaster XS series one from summit. It's not specifically for our cars, but it works.
 
Great stuff guys. Thank you!! Low-5.0 your web site is great, thanks for sharing. I see you changed over to the earlier style throttle body set up instead of the 94/95 style. Pretty easy swap? I've seen that done before, but wasn't sure if the throttle linkage would need to be modified or what all was involved there. Doing it certainly gives you more options for throttle bodies, particularly in the larger sizes. What sort of computer modifications did you do? Currently I have a tune/chip burned by LaRocca's. They did a great job with it, but it ran about $600, and I got the feeling it probably didn't need all that much tuning since it naturally aspirated. I spoke with Anderson Ford and now they're recommending everyone with 94/95's use the Pro-M adapter to change the computer over to an earlier version. I don't know how I feel about that. By the way, how was hood clearance? I noticed you have an aftermarket hood that gives you extra clearance, did you have that prior to the buildup, or did the motor necessitate that? I changed the front end over to 96-98 cobra front end, hood included, which has a hump in the middle to accomodate the cobra style intakes that came on those cars. It gave me a little extra clearance for the Holley intake I run now on the 331. Think that will cut it with 392, or am I going to need more room?
 
The fox TB swap is pretty easy to do, you can see how to do it here, http://forums.stangnet.com/showpost.php?p=4374164&postcount=10
I had some problems with the throttle cable hitting on the fuel rail, but I got it fit after a lot of cutting, bending, and grinding on the throttle cable bracket.

You will need a tune for good driveability and to get the most power out of your engine. Im running untuned on the stock computer right now and it does allright most of the time. The cam also plays a big role in how the computer will act. I need a tune, I just don't have the money for it right now.

Since you allready have a chip, getting it reburned for the 392 should cost a lot less than the original tune.

Fitting a 351W under a 96-98 Cobra hood will be tricky, but it can be done with the right parts. I bought my a couple years ago with the intention that one day I would need it. It had to cut out a small hole in rear of the underside of the hood to clear the intake. You can see this in some of my pics.

To clear your hood, you will need a custom K-Member that drops the engine about 1.5"(pretty sure on that number, but not positive), along with a short intake. I know Sorscode on here has done this before. Maybe he'll chime in with some more info on that.
 
Thanks, Don at LaRocca used a set on his silver 95 conv before the turbo. As soon as i heard that i found a set of used mac headers with the h-pipe for $300 shipped. I hope i remember to set them in the engine bay before I drop in the engine. I plan on dropping it in on sat.
 
my setup is just a basic engine.. not making mad power was never the intent with the car so it was going to be a show car. My motor now consist of a 408/AFR 165's (left overs)/ Edelbrock Performer lower and upper, and a S-trim blower. and XE282 Cam. Mine right now is under test fitting on my 94 GT with a stock hood. All I did was get a K-member to set the engine back an inch and used drop mounts. If I can go back with Poly mounts i'm going to. Just fo now doing test fitting.

Now friend of mine did a complete Cobra R setup and put motor in stock location. Used a R upper intake (same as 5.0 Cobra just says 5.8) and it fits under the 96-98 cobra hood just fine.
 
Interesting point you bring up about MAC headers. I emailed them and they recommended a part number for a set of headers that would fit earlier body styles. I found it hard to beleive they would work, but I think you've validated that they would... although the Kooks are clearly the way to go.

As for the hood, while a K member may not be out of the question, I don't think I want to get into changing the geometry of the drivetrain (i.e. moving the engine back and down a few inches), that sounds like a slippery slope. Sucking it up and buying a new hood (if necessary) sounds like the way to go. Although, I can't believe the Saleen heat extractor hoods offer that much more clearance than stock hood. Admitedly I haven't spent the time to really study one, but the design doesn't appear to offer a significant amount of additional clearance.
 
I just finished mine with a 351 bored .030"over, ported twisted wedge heads, tfs r intake, Ed C. cam, Accufab custom headers, etc etc etc.

Im still addressing some issues in my other thread but it should pay off.
 
331_mustang said:
Interesting point you bring up about MAC headers. I emailed them and they recommended a part number for a set of headers that would fit earlier body styles. I found it hard to beleive they would work, but I think you've validated that they would... although the Kooks are clearly the way to go.

As for the hood, while a K member may not be out of the question, I don't think I want to get into changing the geometry of the drivetrain (i.e. moving the engine back and down a few inches), that sounds like a slippery slope. Sucking it up and buying a new hood (if necessary) sounds like the way to go. Although, I can't believe the Saleen heat extractor hoods offer that much more clearance than stock hood. Admitedly I haven't spent the time to really study one, but the design doesn't appear to offer a significant amount of additional clearance.


IIRC, the Saleen heat extractor clears the 351 because Saleen used a custom K-Member to drop the engine and I think move it back an inch. It's gonna be easier, and probably cheaper to just buy a new hood.
 
I will admit makes the driveshaft a little harder to engage. But take your driveshaft out sometime. See how much room there truely is.. Also look as the crossmember slots. my 4R70W sits all the way to the front of the car in stock location. So set back an inch they were just set to back side of the Xmember.