351w heads on stock 302

[blacksheep]

I have a stock 302 ,that I'm putting in a Fairlane. But, I also have a set of stock 351w heads that I was thinking about having rebuilt to put in place of the stock 302 heads. The 302 has the stock cam in it. Is there any advantage in going to the trouble of using the 351w heads , or should I just stay stock. The 302 will have a 600cfm car, headers ,and weian dual plane intake.

 

[Dirtyrat]

I did a little poking around on one of the stang forums, here is one of the responses to the same question:

late model 351 heads flow the same as the 302 so if you are upgrading the heads the ones to get are the early style.... But the difference are the bolt size on a 351 windsors are 1/2" and they are 7/16 on 289/302...late model heads have 1.78 intake & 1.46 exhuast valves and early ones have 1.84 & 1.54 & also slightly larger intake and exhaust runners.

Ford began using the same basic head casting for both the 302 and 351W in 1977.

These later 351s, originally identified as 351Ks, have the rectangular 302 intake water passages and 6 intake manifold bolt holes. Original 351W heads have L-shaped water passages and 8 intake manifold bolt holes.

Also, the late model 302/351 heads have a larger water passage at the rear,
which means the intake gaskets are different between early and late models.

If you swap "real" '69-'76 351W heads onto a 302 you need to use the
351W style intake manifold gaskets, as the 302 gaskets will leak water
at the unique 351W intake manifold water ports.

 

[zzrodder]

DirtyRat has nailed it, this used to be a popular swap, needing a couple step dowels in each head to center them properly due to the larger head bolt holes in the 351 heads. However, it's getting hard to find the early heads these days and there are so many brand new aftermarket heads in iron and aluminum that are made to fit the 302 without mods that outflow the 351 castings. If you factor in the cost of rebuilding old heads versus the performance gain and ease of installation for new ones, they seem like the better way to go.

 

[HOT40ROD]

There are a couple of companies that make a head bolt set for that swap.

 

[Bamamav]

Yep, unless you have the early {pre 74} 351W heads, they are practically the same and not worth the trouble.

 

[48fordnut]

I have built many with the early 351 head, but the head to use now is the gt 40 head. Not the p head,just gt 40 .There is a real seat of the pants feel over the early heads to this set up.Plus you get hard seats right off.Ford heads have their own centering devices on the lower bolts at each end of the head.

 

[Screamin' Metal]

Yep, FoMoCo was keen on this one, they offered a kit thru the Ford dealers way back when and there were some special washers, bolts and gaskets, the complete shebang for a 20 to 30 horse increase by swapping heads....
The new alum.'s for about $400 are a good way to go....more flow, less weight, etc...

 

[26Troadster]

i think i would rather put 351c 2v heads on the 302 and have a semi home made boss, the boss used the 4v heads.

 

[blacksheep]

Well, I scrapped the whole freakin idea because.......... The number one cylinder had two cracks an inch long in it. 302 out, 429 in. So , I have this 429 with C6 , but it came out of a 72 Torino. Bad heads (D2V), but the motor only has about 70 k miles on it. I'm looking for ideas to freshen it up a bit . Maybe give it a little more umph. Don't really want to tear the motor down right now. It ran very strong in the Torino it was in. But according to my info, it is only a whopping 208 HP . The year before.....360hp. Holy crap what a difference. Any ideas?

 

[26Troadster]

you got to remember somewhere around 70 to 72 they changed the horsepower, from gross to net horsepower, i'm not sure what that is but my thought is from flywheel to back wheels. i bet the 71 and 72 are the same motor, but the 70 will have a higher compression. i would add a intake and headers, then run the snot out of it.

 

[BlueNorther]

the gross rating was done with 160 degree thermostat and iced down intake manifold and no accessories running off the belts and an electric water pump on the dyno.

net ratings had to have the engine as installed in chassis. 195 degree stat., no ice on manifold, complete stock air cleaner and all of the belt driven accessories on and running, including water pump.

these are all on a stand alone dyno, no chassis dyno's.

 

[blacksheep]

I cleaned the 429 up yesterday and noticed a small crack in the timing cover near the main seal. I decided to tear that down and inspect. Just as I thought, it appears that someone put pressure on the cover without removing the two oil pan bolts and cracked the cover. No biggy, just replace the cover. I did have a chance to take a look at the timing set up. It is the same set up they used in 72 models. 8* retarded crank gear. So, I am going to order the straight up 0*'gear set up for a 70 model 429. Is there anything else besides headers and intake that I could do without cracking the motor open?

 

[Screamin' Metal]

Well, Headers, Intake, while your at it, if you change the intake, whil you have the timing cover off....just do a cam swap. Add new lifters.
Other things you might want to do, rebuild your distributor, get a advance kit, change out the springs and weights (5 Horses).... 1" spacer under the carb (8 to 15 horses, depending what else you do).... cam change about 15 to 45 horses, depending....Headers about 40HP, carb change 10-35HP, all those numbers start to add up after awhile....