help 351w what do i need?

[dahitman]

i have an 81 stang that has a 255. i want to swap in a 351w out of a 80's van. is this a good motor to use or should i look elsewhere? if it will work what will i need to drop it in? i am working on a minimum budget (typical) but i want to get it up and goin for as cheap as possible. any help would be appreciated. i am kinda new to this i have always paid for work to get done. now i want to do it myself. thank you.

[eddielugnutz]

It depends, if your coming into this 351W from a 80's van, is it free or do you have to buy it, because if you have to pay any great deal of money, I'd look elsewhere, and it depends on if it's a 2bbl or 4bbl motor, or if it is fuel injected. I'm assuming this motor is free, and you better make sure it's a Windsor and not an M code motor that may have been used in a van, and I'm not sure how to identify it, I think if it's carburated it will have a different bolt pattern on the fuel pump than on a Windsor, I'm no pro.

I just got done doing a 351W swap in my 88lx, the motor came from I believe a 90 or 91 Bronco. It was an easy swap, but guess what, I may be swapping BACK! Compared to the stock 255, any 351 will feel like a world of difference, problably even a 2bbl will feel better, It all depends on the motor, no replacement for displacement has always been a rule of thumb, but in this case, the opposite may be better. Why? because my 351W has stock 8.5:1 compression cast iron pistons , in stock form it only makes about 240hp, and I doubt even that. I think it's actually slower than it was with the stock 5.0 motor with bolt on mods! I am yanking it out, and rebuilding it from scratch and stroking it. That's the way to go.

As for the actual swap, just do a search on this site for 351 swap, in the articles section there is an article written by Marty Kot with all the part numbers and everything you need to swap a 351 in a fox body, I used that for my swap, but mine was fuel injected so yours will be even easier carbed.

Oh shoot dude, I forgot to mention all the other crap man, soemone please jump in and tell me if I'm wrong, but all mustangs 79 through 85 came with the 7.5 rear which is about as strong as a 6 year old girl, trust me, and if it is stick it has the first of the T-5's which holds even less torque than mine (300ftlbs) which means that even a stock 351W like mine will quickly destroy that tranny, hope you have auto!

So no matter how you look at it, you will eventually have to start investing some money into this project, and if your only a beginner, that's going to be much more difficult for you when the rest of the car starts falling apart. Money can not be an option sometimes, I save and wait, save and wait, and buy a part at a time. someone on this site has a qoute, "speed=money, how fast do you want to go?"

just my 2 cents.

[Ieatcamaros]

The easiest way to tell the difference between the modifieds and windsors is to count the valve cover bolts. Windsors have 6 bolts and modifieds have 8. If it were me, I wouldn't give much more than $100 for the motor. It'd be better if it were free.

[Gearhead999]

Also, 351W have the bolts that hold the fuel pump on the block at 9 and 3 o'clock. The 351M have the fuel pump bolts at 12 and 6 o'clock. FYI, 351C's have the fuel pump same as 351M

[dahitman]

thanks for the help and input. yes the motor was free and i payed only 100 bucks for the stang. the car runs now with no problems but i am a speed freak so it is time to upgrade. the car has an auto but i am not sure what kind, i have gotten a couple different answers like it is a c4 or a c6 all i know is that it has 3 forward gears and if i dont row through them it is slow as an import with a fart can. lol but i am going to check on which motor it is when i can get to storage. thanks again though

[82 GT]

Sooooooooo....you bought an engine without finding out which 351 it is? ALso, the fact that it's a 1980 engine means that compression is going to be low...like around 8.4:1 or so. You maight want to look into early heads to get compression up higher.

[Dark_5.0]

This swap is pointless.

A stock 351W is a boat anchor and not worth the extra effort.

A 302HO is way more practical and since you wouldnt have to buy the expensive as hell 351 swap headers it would also be cheaper and every bit as fast.

[82 GT]

It all depends on what year 351w he gets. I agree, if it's a 1980 351w, then I would look for something earlier(pre-74), or rebuild it, which it probably needs already or any other junkyard engine for that matter.

I would rather build a fresh 351w than a fresh 302. At least I would because I'm already setup for a 351w.
It all boils down to how much money you have to spend.
Also, if you opt to build a 351w now, then you're already set for the future in case you come into more funds. Then, you could build a nice 393 or 408 stroker. You would already have all the 351 swap parts by then.
There are several different things to consider before you make any snap decisions like the one you just did by buying that engine without even knowing what exactly it is.
Take you time and think things out first. It will save you both time and money.

[dahitman]

thank you very much for all the input. the only reason i got the motor was that its free. i am going to find out all the info on the motor soon i called my buddy who gave it to me and left a v/m so when he calls i will find out what it came from exactly. also which motor mounts will i need to put it in the fox? and can any one tell me what tranny i have now. it is an 81 with a 255. if it is a c4 or c6 i am having trouble figuring that out.

[eddielugnutz]

Dude, looks like you and me are in the same boat , I did the 351 swap and now it's slower than ever because A: the stock 351 motor I have makes 240hp(maybe), and my old 5.0 had bolts on's and a Ecam that made about 250-260Rwhp.
B: the 351 is about 200lbs heavier than my stock 5.0
C: with hydraulic cam and bigger mass it doesn't run as fast and as hard, doesn't have the throttle response and spunk my 302 had.

You came into the motor for free, but I think it will be a waste of time like mine is, so just bag it and throw it in the garage under the workbench, or in the livingroom and make it into a coffee table, and save it for when you can afford.

Best bang for the buck, 302 swap, and you can find a million helpful articles and illustrations if you search on this site, and on any of the popular mustang magazines, like 5.0 mustangs/superfords, muscle mustang &fast fords, etc....
That swap is the easiest and the ultimate bang for the buck, a 302 has awesome potential for cheap. Check out the sites and search for articles.

your car only came with a c4 I believe, in 81 yeah, a c4 most likely. I think the c4 is just a square pan, and the c6 has an extra side to it and is not shaped the same, that's the easiest way to tell. the c6 has 17 bolts on the pan, and the c4 should have less.
Just remember, whether you put in the stock 351 or you go with a 302, it will still suck donkey nuts with an automatic and a stock 7.5 rear, the performance is terrible in stock form, my buddie's 90GT automatic with 3.08 posi ran a 16 at only like 80mph it sucked so bad. and he had some bolt on's and thought he had a bad ride. So while being a bit faster than the 255, it will still be pathetic and dissapointing without gears.
cheapest route:
get a 5.0 shortblock for about 1,000$
Trick flow twisted wedge heads, 1,000$
use the recommended cam from trick flow, get intake carb, and all necessary hardware for 5.0 swap, should make at least 300RWHP, and if you get that fully assembled 8.8 rear with 3.73 gears from year one, it should be a low 13 second car on street tires.

But if you go the route of putting in a stock 351 in a c4 with a 7.5 rear with no gears, it will problably do a 16 second run if it even makes it off the line without breaking the rear, Choice is yours man, good luck. I know because mine is slow as hell. I'd problably be lucky to do a 15 with this piece of crap, and I got gears and traction! RRRR, why didn't I listen to the guys on this forum sooner!