I have a 302 with 351w heads and a 351w firing order in my 72 f100, Obviously this is a mod, anyone ever heard of it and what is the purpose, i dont even know what any of the tune up specs for this would be!

 

it not a bad thing, whoever built the motor used a 351 cam which has a diffrent firing order than a 302.

 

What are the casting numbers on your Intake manifold? you may have a 351 instead of a 302, they were both common & available after 68 in the F-series.

FBp

 

cast # is D30E-9425-AA but also stamped on the intake is the firing order of the 302 (15426378) Can this be built up for some nice horse power?

 

I saw such a beast in a RV once. Not sure about the heads, but it had the 351 firing order. Might have been a factory combo for HD use????

 

hey im new here but i have a 72 myself with a 351W me and my dad are restoring it but from what my dad says they can be built into beasts

 

Next to the Y Block the 351W is the best of ford IMO. But than tere is my 390 biult to 427. FE's are awosome.

 

For some reason the 351W/5.0L HO firing order reduces stress on the forward main bearing, compared to the 289/302 firing order. In the 60's they sometimes limited ignition advance on 289's, but that's less needed with the 351w firing order.

 

So the general consensus is to keep this motor over other swap options?

 

In my opinion, there's nothing wrong with using the 302 as the foundation for an F100 powerplant. It's a great engine. Depending on how wild you build it, you could have anywhere from 200 to 400 naturally asperated HP from that 302 shortblock. Tourqe could vary from around 300 to about 385 ft-lb's.

A 370-400 Hp 302 will require aftermarket AFR or TFS heads, and an Edelbrock RPM, or Wieand Stealth, type 4bl intake, but so would a 370-400 horse 351w also require these type of aftermarket parts.

The cylinder heads are the main limiting factor, and they are the same for both motors.

A 351w, or another larger displacement alternative's main advantage over a 302, would be the little extra low end grunt coming right off idle, due to the extra cubes.

 

351W heads on a 302/289 are an old school swap. There didn't used to be much in the way of affordable Trick Flow and AFR heads. The 69-74 351W heads had the largest valves installed in small block Fords. As a plus the 69-70's weren't drilled out for EGR passages though the famous casting "bump" in the exhaust port was there. Today the cost of doing a really good port/polish and rebuild of the old 351W heads is almost that of a a decent pair of aluminum aftermarket heads. Any of which will pretty much outperform the modified W heads right out of the box anyway. Not outform by a big bunch, but still...
Outdated hotrod tech today but still valid. Back in the day folks also used to swap 302 cams into 351W's because there were a much wider variety of cam grinds for 289's and 302's.
I have a pair of home-ported '69 heads on my truck's rather newer 351W engine. I like em just fine and don't see where I need anything more. Besides, I got them free.

 

for a relatively light f100 2 wd id say the 302 youve got is fine, if it were a bigger truck or a 4x4 then id say go a bigger engine like a 390 or 460... your 302 should be able to get close to 20 mpg if youre light on the gas and have highway gears, if you went to a 390 itd get about 15, on a 460 you could get about 12, but a bigger engine is a whole lot more power... so it depends on your intended use- if youre just running around town with it doing errands and such id stick with the 302... if youre towing much of anything with it get a 390 or 460

 

In stock form the old 351w 4bl heads don't flow quite as good as stock GT40 Cobra heads. With a professional port job, they can be made to flow about as good as out of the box GT40Y aluminum heads, or Edelbrock Performer heads, or Holly Systemax heads..ect.. That's still significantly less than the out of box TFS or AFR heads. Nonetheless, massaged 69 351w 4bl heads could potentially support up to 450 HP. As rule of thumb, you will normally get about 80% of the heads potential from a steetable package, so a streetable 360 HP 302, using ported 351w 4bl heads, is entirely feasable.

We have numerous dyno results of stock shortblock 380-400 HP 302's (some even using the Stock HO cam), with the TFS and/or AFR heads, but using the 351w heads (provided they are the old 69 4 bl castings, not later 351w heads, and they are pro ported), could come fairly close.

Don't sell the 302 short. What's possible today with a SBF, compared to times past, is absolutely revolutionary. There's not that many streetable 400 HP BB's out there. A emissions legal 302 capable of cranking out about 1.3 Hp per cubic inch, sipping pump gas, is not all that uncommon these days.

Of course a big block has more potential. A 460 cylinder head flows about the same as out of the box TFS or AFR small block heads, but ported they could probably support up to 680 HP. Stock 390 FE heads with a 2.04" intake valve, also flow at about the same level of unported TFS or AFR small block heads.