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390 S code engine,

5.5K views 18 replies 9 participants last post by  multi68stang  
#1 ·
hey guys so i have a 67 mustang fastback S code, and i have the S code motor, i dont want to put the stock engine in because i want to do a eleanor but i was thinking of using my 390 and stroking it to a 427?

is that a ok idea?

what kind of power will i be looking at?

sorry for the stupid question
 
#4 ·
Kind of hard to gauge w/o more info. If you stroke it there would be more low end grunt (torque) but if you use the gt heads it may not be what you want. The combination of stroke, heads, pistons, cam and intake will more of a factor. Just pointing out that the "S" manifold and heads are very much a limiting factor.
 
#5 ·
Pull the 390 and put it to the side. Then build a 408+ Windsor. It'll be less expensive and easier. FE engines require a bit more knowledge and tricks to get right.
 
#6 ·
I don't know if you could stroke it to a 427. The FE 427 & 390 both have the same crank throw, but the bore is .180 larger for the 427 which would make cylinder walls impossibly thin, if it could be done at all. When I had my 390, I had it bored .080 over and dropped a 428 crank into it, turning it into a 428. I drove it for over 7 years as a daily driver before I had to sell the car and it still ran strong.

Just another option -

Mike
 
#7 ·
390's can be found some what cheap so if the motor is original to the car then I'd find another 390 off the craigslist to build & store the original motor. The 360/390/410 all share the same block with different internals, the 360 has a 352 crank with 390 rods & 360/390 4V pistons (same thing), 410 has a 428 crank with 390 rods & 410 pistons (some truck 390's had 410 pistons installed from the factory with the 390 crank ending up with a 8:1 CR).
The exhaust is really restrictive on the FE Mustangs along with the top end. A aluminum RPM performer intake is a must with a FE (not just for power but for the weight loss on the front end), as for the heads the only good set of stock heads are CJ's & C6AE-R heads (these need CJ sized valves installed) but other than that I'd go with aluminum.
As for stroking the motor I'm going with a 445 stroker kit for my 390, bolts right in the block with no machine work needed (I'd still have it internally balanced though).
If you're wanting to build a FE then I'd go to SurvivalMotorSports.com, Barry is considered a FE guru.
 
#9 ·
I'll second the call to Survival. And honestly, in the end that stroker kit isn't a bank breaker if consider the cost of the components to just freshen up the 390. And you have new parts that don't have 40 some years of metal fatigue. While that's probably not an issue, anymore I'm not as trusting of stuff that I have no history on. You can't tell what cranks in the engine when it's in the car without doing a bit of work, and me personally would have no issue throwing a stroker kit in an S code. What will hold you back are those stock heads. They'll take some semi-serious part work to flow what an Edelbrock or CJ head would flow, and I don't think a set of CJ heads would hurt your value if you have the stickers available. Unless you have some 100 point show car. The stock exhaust manifolds will have to stay behind too if you want any decent power out of the engine.
 
#12 ·
I have thought of using a 351w but I was quoted a 351w stroked to 408 10-15k and I think that is a lot just for the motor. Or is that going price?
Maybe for a turn key 600hp+ engine with carb and ignition system. Otherwise that is way too high for a longblock.

I suggest researching this more on your own with google before making a decision.
 
#13 ·
If it's not the original motor then I wouldn't hold back on building it.
Cam wise I'd contact Barry & ask after explaining how you will drive the car. As for rocker arms I'd recommend Harland Sharp or T&M(? I think that's the brand... it's been a while) as they offer their rocker arms with needle bearings where companies like Comp Cam's rocker arms mount directly to the shaft without even a bushing.
As for the heads it would probably be better to just go with a set of Edelbrocks or FEonly heads as by the time you hunt down a set of the heads I mention in my previous post, purchase them, & have them rebuilt you might end up with spending less if you go with a set of aluminum heads. Another thing to consider is that with a set of aluminum heads, intake, & water pump the 390 (625lb) will weigh about the same as a 351w (520lb).
 
#14 ·
thanks man ill check them out, do you know how much harland sharp rocker arms are roughly?

with the canadian dollar so bad it will cost me alot more than you guys, unless they like canadian money haha

i do have a Police interceptor intake, do you think i should use that? or buy one from FEonly?

thanks
 
#17 ·
The HP number is just for bragging. My .020" over "390" with a 4.125 stroke crank doesn't make 500hp but spins the tires in 4th gear at 50mph without at least a 200tw tire.

Get a stroker kit from one of the FordFE engine forum vendors, about $2000 now and will come with a very good custom piston that can be had in bores other than .030" over. A set of aftermarket heads that flow 270-300 at .600" lift a Performer RPM and custom cam matched to all the above and you should get into it for less than $6000 in parts ,use local labor and assemble it yourself. If you have to pay somebody to put it all together make 100% sure they have built PERFORMANCE FE's before.

I started my FE build with NOTHING 9 years ago and had it in the car and running for $9200. I had to buy every piece.
 
#19 ·
The 351w is a good motor & with a stroker kit can easily make big block power. The 393 can be done by installing a 3.85 stroker crank with 351 rods & 302 pistons. The 408 & 427 kits cost about the same & the power isn't to much different between the two. All stroker kits for the 351 require machine work to be done to the block & no matter what motor when installing a stroker kit I'd recommend having it balanced.
However with a 351w you really can get away with just building a stronge bottom end but IMO the biggest problem is none of the Winsors have a good performance top end. Build the bottom end to be able to handle turning 7k & focus on building the top end.
Originally I was going to build a 408w for my '68 but in the end I went with the 390 for the wow factor.