I hear that the 1985 - 1987 351 H.O. was a real beast with the 4-barrel carburetor and the marine cam. When the EFI 351 came along in 1988, it wasn't near as strong as the 351 H.O. Not until the 351 Lightning came out in 1993 did the 351 get any real power back. Does anyone know what the cam specs were on these two motors? And what transmission and gear ratios did these two trucks have? Which truck had the better heads?

Which of these motors was the most powerful, and which one would you rather have?

 

Lightning ONLY came w 4:10s and their cam SUCKS. I cant wait to rip mine out in put in a 5.0 roller cam

 

The 351HO got a slightly bigger cam than the Lightning but it wore the same small valve low compression smog heads every other motor from the era got and the stock exhaust was a complete cork, while the Lightning wore GT40 heads and the F4TE block is roller ready so overall the Lightnng was better setup. Cam specs are similar with 260ish intake duration for both but the for some reason the Lightning cam only generated 0.416 total valve lift vs 0.445 for the HO cam so there is a lot of potential left on the table.

 

I had an 86 F150 Supercab with the 351 H.O. It had a C6 with a NP208 (I think) and a 9 inch rearend with 3.50 or 3.55 gears.

Whether the 9 inch was stock or not, I do not know. The original owner was a concrete cutting company form Reno or Sparks, NV.

While it ran allright, (it had a fairly new crate motor when I got it); it was a beatup old work truck, not a hotrod.

Robert

 

Why. It's still a tiny cam. Spend the little extra and get a nice roller cam of you're gonna spend the time to replace the cam.

 

The truck is going to stay speed density. I am not getting involved with going to mass air.

And 5.0 cams are a dime a dozen

 

The 5.0 HO roller cam is a good upgrade for the lightning....and can still stay SD...

 

I just feel as though it isn't worth the effort to tear half the motor apart for such a minimal gain. I'd rather spend the 180 dollars extra for a very nice and noticeable gain. There are plenty of sd compatible cams out there that are much better then the ho cam. Yes it's an upgrade but not enough for me to yank the motor apart that much for it.

 

It is quite a noticeable gain. IIRC just the cam alone will pick up .4 sec in the quarter mile. But I will have my heads off so i will be doing the 5.0 cam while in there

 

The Mustang HO cam is very close to being a roller version of the old 351HO cam so in this swap you gain more valve lift but also a pretty significant reduction in rotary friction inside the motor which also puts more power to the ground, it's impressive actually just how much faster the throttle response is with a roller motor. But the HO cam still falls a bit short of utilizing all the airflow potential of these heads so I'd suggest adding 1.7 rockers while you're in there.

 

Yes,, that is on the list too. Also dumping the GT40 heads and putting some AFR 185s on

 

Oh wow.. it's definitely gonna need bigger injectors and a tune then too, that's a big step up in airflow from stock.

 

Oh come on man.
Why on earth would you put a very nice head like that on and limit the whole works with an iffy cam choice.
I am aware that a similar head and the ho cam in a 302 (along with perf rpm intake and worked over carb) made 400 crank hp, but you're going to be needing a custom tune anyway.
I am sure you'll be happy with the results, but it's potential is so much more then what you're asking it for.

 

no need for a tune. O and a sq blower will be going on at the same time