It really depends on the year of the 351..Unfortunately that looks like a late 70s or early to mid 80s which were nothing to write home about in stock form..The heads are absolutely terrible with 302 sized valves and huge combustion chambers that kill compression...
With good heads(aftermarket) and good intake,cam headers etc you can easily knock out 400hp or more depending on how crazy you want to get...The 351 blocks are pretty stout but get weaker as they get newer..Any of them should still be good to around 600hp though...The roller blocks were made starting in 1994 I believe..They aren't the strongest of the blocks but you can easily swap in a roller camshaft and lifters...Older 351 will require a set of retro linked lifters which are fairly expensive compared to stock ford units..
That engine as it sits would not be an improvement over your 302..It looks very dry and dirty inside so I would only consider it as a block that you can start a new build with..

Its an easy swap but I wouldn't call it a direct bolt in..The mounts will work and the trans will bolt right up...The accesories will need some adaptor brackets due to the taller deck hieght..The headers will bolt up to the heads but may not clear the chassis anymore since they will sit higher and wider in the car on the 351...
The stock pulleys and brackets from your 68 302 will not work on that engine either unless you swap your entire front setup from the 302 onto the 351(balancer,waterpump and timing cover)

I can't see in the pics if the oil pan is a front sump or rear..If its a rear sump you will also need to switch it to a front sump..The one from your 302 will not fit..

 

A 351w block of any year can handle 700+hp with no problem. 800 hp is usually the limit to a stock 351w block depending on what rpms you are turning or if you are using nitrous or forced induction.

HP is in the heads and intake. The camshaft just brings everything together. My 357w pictured in my signature should make around 530hp at the crank with a relatively mild solid roller camshaft. Stroke the bottom end for more cubes and your ability to make power goes up infinitely from there.

How much HP do you want to make and what type of budget are you looking at having?

 

I really wish I could make 550-600 to the wheels on all motor but my car part budget is much less than it used to be and I still have a good amount of other stuff to do to the car. Maybe your set up would be more realistic. My fear with going 351 is headers, and keeping all my current accessories. I have a/c and PS. I have thought about converting to manual steering for simplicity unless it's a costly swap but I want to keep the a/c and I refuse to drop $1k on a serpentine conversion. I wonder if I could use a stock serpentine belt set up if I ditched my PS and converted my Sanden's pulley ? This has me contemplating just going with a used 302 roller block and stroking it to a 347 instead.

 

I run a 1972 block with AFR 205 heads and a big solid roller cam. It hasn't been on the dyno yet, but multiple sources have told me that I should 600hp at the crank no problem, if not more. But be aware, the guy who I bought my car from paid around $14,000 for the motor according to the receipts he gave me. Making power isn't cheap and it only get exponentially more expensive the more power you make. While someone could build a motor that makes more hp for less than what's in this motor, the guy used only top shelf parts and put a lot things in to increase the engine's durability and lifespan.

 

The 351W has proved to be one of Ford's most lasting and popular designs. Even in 1970, Ford listed over-the-counter parts to replace the intake, carb, cam, and valves to increase power output of the 351W 2V more than 100 hp. That was using the stock iron heads, because nothing better was available then.

 

man that sounds nice

yeah I had a 2000 GT Mustang with $40K into it. It was fast lol but yeah I know how all that goes but I have so much other stuff I want to do to my car I just keep thinking there has to be a good way to make medium to big power on a budget. I have a good 302 now but I guess it's basically useless for a foundation.

my old baby with +700 hp at the wheels out of 281ci

 

what could you do with something like this ?

FORD 351 WINDSOR ENGINE F150 F250 MUSTANG VAN: eBay Motors (item 140456178649 end time Nov-19-10 00:36:27 PST)

what could it make with a intake carb and cam only ?

and heads on down the road ?

any way down the road with a stroker kit ?

 

or this ? do the roller motors make more power in stock form and modified ?

Ford Mustang 1969 1970 351W Windsor Engine 4BBL 69 70: eBay Motors (item 300462211462 end time Nov-29-10 08:37:13 PST)

 

With only a couple of years as exceptions the stock 351 was not much. Not much more than a few ponies better than the same year 302. Which means pretty anemic.

As others have said though they can be made into an astoundingly powerful motor as long as you have cubic dollars. They can be made into as much as 427 CID. How fast do you want to go?

 

I have a good 302 now but I guess it's basically useless for a foundation.

Not at all.

The 302 is a great foundation for building a strong engine. The aftermarket is ripe with performance parts and at some fairly reasonable prices.

How about stroking that 302 to 347? SCAT makes a kit that sells for ~$1,800.

You can buy vintage style Paxton superchargers for it. Modern aluminum heads. Roller cams.

 

well I'm not sure but I dont think what I have now is even a roller block. It is a 1986 302 I believe. I would just think it would make more sense to start a 347 build with a roller 302 block then get the stroker kit and heads / cam. I just didn't want to spend $1,800 on a stroker kit if I could spend that on nice heads for a used 351 motor and be way ahead that way. There are used 351 motors for as little as $200 like the one I posted in at the top. But then again I dont know what all is even involved in swapping a 351 into my car.

 

I would look at that 86 block really closely. The 86 block should be roller ready if it is not already a roller block.

Swapping the 351 in your car is not really hard. I guess the biggest problem is mating up the accessories and the exhaust. The exhaust will cost some real dollars if you go to headers. If you use the stock log manifolds you will still have to mate your exhaust up.

 

I would look at that 86 block really closely. The 86 block should be roller ready if it is not already a roller block.

how can I tell by looking at it ?

 

The lifter bores are deeper and the intake valley has two bosses where the roller spider was mounted.

 

where is that casting number located ?

 

I changed my post very quickly after I realized the casting number was actually for the 86 heads.

I guess you can check the casting date above the starter to make sure it has a date in the 1986 production year.

 

The only advantage to the roller block is that the factory roller lifters are relatively cheap...The older blocks from the 60s and early 70s are stronger if you are building an all out performance motor...

 

It all depends on what you want. I have a 302 now that will flat out roll. It is well built, but I want some more power and I'm looking at the Keith Craft 408 crate engine.

However, the option to rebuild my 302 and stroke it to 347 is still on the table since it can be done for less $$ since I already have a great set of heads (Dart II Seniors).

This Scat 347 kit is only $900:

Scat Street/Strip SBF 347 Rotating Assembly [1-94165-1] : AD Performance, Your Source for Longblock Performance Parts

 

If you want to make 550-600 rwhp NA then the stock 302 block is out. 302 blocks like to start spliting at the 550+ hp mark, and this is at the crank, not the rear wheels. If you want to make the kind of hp you stated then a stroker engine using a 351w block is the only way to go if you are looking at being NA. A 418 stroker kit with the shorter rods and the 4.100" stroke is the way I would go. To make your hp goal you will need around 750hp at the crank. You will probably want to talk to someone who has more experience with stroker engines and stock blocks as to see what rpms you will be able to spin the bottom end to and keep the engine together. Jim Woods of Fordstrokers.com would be an excellent person to talk to. My feeling is that you will have to spin this engine up quite high to make the hp you are looking at making and perhaps an aftermarket block would be best.

Serious heads and a very good intake will be a must. Total Engine Airflow www.totalengineairflow.com sells a set of 245cc Trick Flow High Ports which would be my suggestion for the cylinder heads on an engine like this. This would not be a cheap build in the least. You would need at a minimum a Super Victor intake (wont fit under a stock hood) or a well ported Vic Jr. This is going to be a $10k+ engine even if you assemble it yourself.

 

what can you do with a stock 351w ?

irate:irate:

 

irate:irate:

lol nice :thumbsup::thumbsup:

 

If you can find a old stock or used Ford Sportsman block its the cheap way to go for big hp. It wasn't nearly as expensive as a full race block, but had better alloy and better mains. It could easily handle the hp without breaking bank and was a roller to boot.

If you go after market block, then seriously consider the Cleveland mains as it will reduce friction and heat at high rpm's. Everyone makes a hoot to do about this, but I shift my BBF at nearly 8000 rpm's and it doesn't complain. Of course its crank is $3000 for reference.

Street or drag I would go 351w over 347. Saying that, I'm going 347 for open track car to save weight but will have to go race block. It just has so much potential....look at engine master's challenge and the Cleveland 3V heads to see where a 351 can go if budget is open. We're talking 700hp NA on pump gas! We are also talking serious money...Kaase had his small block up for sale on the website recently

 

OK so could I run all of my stock 302 accessories, brackets, timing cover, water pump etc with a 351 ?

would I have to run stock style log exhaust manifods since I want to keep my power steering ? if so are they too restrictive for big power ?

how much HP can a stock 351w short block handle ?

 

Brackets won't fit due to the difference in width between a 302 and a 351. Timing chain covers interchange. You can run headers with power steering. Might just have to use a drop bracket on the power steering ram. Yes, stock exhaust manifolds are too restrictive even for an engine with minor mods. I run around 600hp on a 1972 block. My block uses all ARP studs and has a main stud girdle. I'm sure there are others with higher levels of hp on stock blocks.


My engine

 

is there a set of heads that I can put on my 302 now and also use them with a 347 build or on a 351w later ?

 

How did we get from 600 rwhp to throwing heads on a 302? You really need to get an idea of what you want to do and how much money you have to do it with. Of course there are heads you can put on your 302 and then on a 347 or 351w but they are two different animals. It would be a compromise either way, IMO. You will be money ahead if you run what you have now and save the money up to do what you really want to do in the future.

 

6t9 is probably the smart money here, but to answer your question directly there are a few points to look at.

302 and 351W use different size head bolts. This can be worked around by buying 1/2" bolt heads for the 351/302 after market block and run bushings for stock 302 block.

If you size it ideally for the 347/351 you'll have a dog on the bottom end with your 302. Sure there are compromises that would work like a 185cc AFR could straddle both cu in if 500hp range will make you happy in long run. WATCH your stock pistons with any size cam using heads with bigger valves, rotated valves or varying angles of valves. Twist Wedges wouldn't be worst choice for your application but they won't clear stock pistons with much lift.

Answer is YES. But, should you.....maybe not. Why not just pick up some used parts for now to make the 302 interesting and start a serious research on what you want to spend the big $$$ on in the end.

Depends on application as I've said before but if you want moderate cost 500+hp then you better plan 351W stroker.

 

WATCH your stock pistons with any size cam using heads with bigger valves, rotated valves or varying angles of valves. Twist Wedges wouldn't be worst choice for your application but they won't clear stock pistons with much lift.

Twisted Wedges would be perfect for his application. They create a MORE piston to valve clearance, because of the rotated valves. Not less.

 

yeah I was thinking I could throw some head on my car for now that could be usable later while I gather parts for a 347, or 351 build. I'd really like to take my time a build a stroked 351. I'm just concered becasue I'd like to keep my a/c and power steering.

 

My advice is don't get too caught up in the hp numbers or the bigger is better thing unless you are racing...I almost drove myself crazy trying to decide on which direction to go with my build..I finally just decided on a power level and got the parts that would get me to that level...Have you ever driven a 40 year old street car with 500hp?...Or even 400?...I can tell you having that much power in an old stang is a handful at times..You can rarely ever use that much power on the street without getting busted or running the risk of running over somebody in a much slower moving vehicle.....Keeping your power steering and AC shouldn't be too big of an issue if you pay attention to the front dress and your brackets...You can build a "mild" version of a stroker that will have awesome low and mid manners and run all of your accesories without a fuss and still knock down 450ish hp....