This might sound dumb but I have to ask. I have an 87
F150 with a blown 302 in it. Would it be worth the trouble
to put a 351 in it or just replace the 302. I don't know
what problems would present themselves with trying to
put a 351 in place of the 302. I do not plan on any heavy
hauling or towing. That is why the 302 is dead. No more of
that.

Thanks for any input.

 

first, the only dumb question is the one that was never asked.

Second, I beleive that the 351 should be a direct bolt in replacement for the 302. Not sure & if I'm wrong someone will deffinetly correct me.

third, the 351 is a powerful engine but the 302 can be as well if you plan a proper rebuild.

 

I figured the 351 would bolt up OK but what about
the fuel injection? Is it the same or do I need to worry
about new injectors, fuel pumps, chips, etc? I am a
relative cherry when discussing this kind of stuff. The old
motors were no prob but injected stuff and the like makes
me nervous.

 

everything will line up perfect (my dad has an 88 Bronco like mine, mine is 302, his is 351, everything is run the same way and in the same place)

But a blown 302? Why do you want a 351?!

 

I believe he means "blown" as in worn out or destroyed, no "blown" as in Supercharged..

When I first saw the thread title, I thought it meant supercharged as well.

 

the 302 bottom intake will not fit onto the 351 so you will have to have a fuel injection bottom intake, but everything else will work ok.

 

The 351 is a better truck engine, as far as torque. The 302 nearly matches it in horsepower, but it doesn't have any torque until upper 3 to 4 grand. But since you don't do any towing, a 302 shouldn't be a problem for you, but i'd personally rather have the 351.

 

also you should consider fuel milage too. i get 10-12 with my 1991 F-250 4X4 with a 5-speed overdrive and 4.10 gears

 

Hi Guys,

Thanks for the replies. I have a couple of more questions,
just to make sure I understand what is being said.

Regarding the bottom intake. Will my 302 throttle body
assembly bolt up to the new bottom intake? Will the old
injectors work with the 351? And will I need to make any
changes re computer? Also, will I need to make any changes
in rear-end gears. I have a stock 4 speed (manual) in my
truck but am not sure what actual gears are in there. I really
don't want to get involved with changing gearing unless I
really have to.


Regarding the "blown engine" issue. I meant toasted
engine.

 

The throttle body should work, but I think the ports in the manifold between the upper and lower are different. With the computer, I've heard of people using the stock 302 computer for the 351, and I've also heard people had to switch them out. I'd leave the rear end alone until you get the motor in there and see how it drives.

 

the upper intake should bolt right on to the 351 bottom intake

 

I think someone posted about this a couple weeks ago. The 351 has round ports and the 302 is more rectangular. It's probably just as easy to get upper and lower at the same time as to just find a lower.

 

the lightning manifold is the only manifold with round ports, unless you mean the 351 manifold has more of a rounded rectangle shape to the ports, but I thought the two had the same shape of ports.

 

That's what the 5.0's look like, and I think that the 5.8's look something like this:



I am not 100% sure, but I'm pretty sure they are different.

 

I have done the 302 to 351 swap in an 89 bronco.
Things you need to change:
Engine.
If speed density (ie no sensor right next to the air filter) 351 computer. (get the speed density to mass air conversion kit, it comes w/ a computer, plus you can play with the motor alot more).
5.8 upper and lower intake, and injector fuel rails.
Fuel pump (I havent' changed mine yet, so mine is running lean).
?torque converter (didn't do it myself so not %100).
Belt.
Wiring harness. (add canister purge valve, remove ps pressure switch)

Things you do not need to change:
accessories (alternator, ps pump, ac compressor, air pump)
injectors
motor mounts (I would while I had them out).
bell housing.

It is a a fair amount of work, but worth it in my opinion.

Good luck