Im trying to build a 351 to go in my 91 F150 (see sig), long story short the 408 I built for it isn't what I want, so I want to build just a basic 351 that's better than stock but not crazy. It's gonna see daily driver duty and some light off-roading, nothing serious. I'm wanting to do this as cheap as possible but not skimp on what needs to be done.

So I need some help picking out some parts.

Parts I have:
Complete 351w from 1990 Bronco
GT-40 heads about 60k miles on them
Edelbrock Performer Truck 5.8 intake manifold

Parts I need suggestions on:
Camshaft
Pistons

Miscellaneous questions
What kind of things should be done for those heads? I am aware of the different head bolts. Should I have them completely rebuilt, new valve-springs and such? Ill want to do stem seals at least won't I?

Should I get new rods or can I re-use the stock ones?

 

If this is a DD then unless those heads have alot of hard miles on then you could reuse the stock springs. I had a 1993 Cobra Mustang with those heads and it would rev past 6K with no problem. I have another set that I plan on putting on a 5.8L in my van and the spring will be left stock.

If your block is a 1990 then it is not a roller block but I could be wrong. One of the best up grades you could do is to go with a roller cam. To do this on a non-roller block you will need to get a set of "retro-fit" hydro roller lifters. These are not cheap but if you get these lifters you can use any number of roller cams from the 302 V8. For a DD the stock HO cam from a Mustang 302 will work fine, the Cobra cam from the Cobra Mustangs will work even better. By the way that's what I'm putting in my 5.8L.

You can buy a new cam, and there are many out there to choose from but I went used to save some money. I have both a HO302 and Cobra cam that I can install in my 5.8L. I will be going with the Cobra cam. I bought both for $50 shipped! The lifters were bought used as well for $225.

A stock replacement piston is all you need just make sure that the combustion chamber of the heads is less then 65cc's. If you want a higher compression ratio then you can mill the heads.

You can do a mild port & polish on the heads. Slim down the valve guide bosses, smooth the transition from the port to the valve seat, add a 3 angle valve seat, have the valves back cut as well and polish the combustion chambers. If you do this last step then you will need to mill the heads to gain back some compression that you loose doing this.

With the parts you have plus a good cam and a set of headers you should make at least 300 HP with good low and midrange torque!

 

Ok so I got a call from the machine shop and the block needs to be bored 0.030".
What kind of pistons should I go for, with the heads and intake I have?
Also anyone else have any suggestions for a cam?

 

Flat top pistons with valve reliefs that produce about 9:1CR with your heads, and the Crane 444232 flat tappet cam and lifter set, it's a little bigger than the HO cam and doesn't require the expensive roller parts, it's also fully SD EFI compatable.

Out of curiosity.. what about your 408 isn't what you want? The only downside I can think of would be it's thirst.

 

Thirst is one, but Ive had a bunch of problems with it also. Theres something wrong with the cam gear because its eating the dist gear(its the right material and correct placement on the shaft) plus i have a large vacuum leak, pretty sure its from the intake manifold. So Im tired of tearing it apart basically. Im gonna throw a different cam and a carb on it and its going in my 57.

I was thinking about throwing some 0.030" over stock pistons in it and then I can run cheap 87 fuel. Would that be kinda dumb move, seeing how I need to get pistons anyway?

Its already MAF and I thought it was a roller, isn't it?

 

"Stock" replacement pistons will often be a flattop design with 4 valve reliefs, these produce roughly the same net CR as the factory dished pistons since the total piston "dish" volume is about the same. Nothing wrong with doing this IMO, I'm not a fan of having to put premium in a daily driver.. it simply doesn't pay off with these trucks because the computer isn't smart enough to automatically take advantage of the higher octane you have to manually setup for it(advance the timing), and then you can't run regular if you get in a pinch. 5.8/351 blocks didn't go roller until 1994 so your '90 is a flat tappet.

 

Thanks, Conanski.

Will I need different valve springs or will the stock ones work with that cam?

You have a rough estimate on what kind of power this combo would make? Basically stock bottom end with the GT40 heads, Crane cam you suggested and intake. It'll have the long tubes and true dual 2.5" exhaust.

Not too important really, just kinda curious.

 

Don't mean to Hijack the post here or anything but I'm also doing a rebuild on a 5.8L except mine is from a 96' XLT bronco. And I'm completely lost on what kind of cam I should get for it. jimbbski Recommended the HO302 cam along with Milling down my heads but then I saw Conanski talking about the "Crane 444232 flat tappet cam and lifter set" and it got me interested in that.

 

Will I need new valve springs for that cam?

 

My two cents is stick away from flat tappet cams.... Unless you want to worry about adding additives all the time... I would recomment going to a roller and spending the extra money.... All you want/need is the basic .480 lift cam for a good stock rebuild imho.... Conanski always give great advice...

 

You should always use new springs matched to the cam you're using.New retainers and locks are a good idea also.It's much easier to do with the engine on the stand than in the truck.If anything lets go in the valve train it will take other engine components with it.Cheaper to do it now than later.

 

One trick that can work pretty well if you want to do a roller on the cheap is to use 5.0 mustang roller cam with 1.7 rockers.... Works well on a truck for a roller that a lot of time you can pick up for nothing..... It is not as good a cam as a crane or comp cam with .480 lift... But its pretty good.... Also always change the springs....

 

If it's an F4TE block, then yes, the components from a Mustang or roller 5.0 truck will work; lifters, dogbones and spider. Otherwise, you're looking at retro roller lifters which is a bit expensive. Another option is to use the components from a rollerized 5.0, with a small base circle cam, and you will need to drill and tap the block to fasten the spider.

 

The "wear problem" with flat tappet cams is a bit overblown IMO, I have one of the Crane cams I keep recommending and it shows absolutely no wear with maybe 50-80k miles on it. It could be that there are issues with some of the cheap chinese cores that have flooded the market as of late but that's just speculation, overall I think if the cam is broken in properly it won't be an issue.
This Crane cam doesn't need "upgraded" springs.. the matching springs are pretty close to what comes stock from Ford, but if you're rebuilding the motor it's a good idea to replace all wear parts and valve springs are definitely a part that wears out or fatiques over time.

 

On your motor the Comp 35-349-8 would be the HO equavelent(1500-5500rpm) with a bit more lift, note that it will require matching springs/retainers/locks/ and valve seals, the stock umbrella seals won't fit inside this double spring kit. If you want something with a more truck oriented powerband(0-4500rpm) pick the Comp 35-512-8 instead.
Personally I wouldn't put a dime into the stock heads, if you want more output then they provide.. about 280hp with the above cams, swap on some used GT40s. In all cases if it costs more than a few hundred dollars to make any "stock" head usable look elsewhere, it's money wasted when you can have brand new heads like the RHS or Dart irons for a little over $1000 a pair... both of which outperform the stock heads by about 100%