I recently decided not to lift my truck because of lack of power and bought me a small gas saving car for a new daily driver. over the summer the plans for the truck in my sig are to pull the motor out and do some work to it. so far the plans are:

-a pretty big cam
-port and polished gt40/gt40p heads
-port and polish stock intake
-hooker long tubes with full exhaust
-possibly a 3 angle valve job
-stage 2 B&M shift kit

thats the initial plan for right now because of budget. later on i plan on different roller rockers, bigger TB, larger injectors maybe, and a stall maybe.

im just wanting to do the above for right now and im trying to get together a parts list and decide on what cam and what set of heads.

im going to try and think long term meaning when it comes down to picking a cam and what not i want something that later on when i put on other parts i will still benefit. for example say i choose a cam that needs a stall or different roller rockers to make the most power but still makes an improvement over what i have now.

with all that being said what cam should i go with? i dont plan on replacing the rocker arms for the first part of the build this summer. how big of a cam can i get without havign to get different push rods and valve springs and what not?

also which heads should i go with? the gt40's or gt40p's? whats up with the p's? they dont have a hole for something? if thats smog related i plan to get rid of the smog pump and what not anyway.

im hoping some of you guys chime in and help me out. its going to be a somewhat budget build or i would not even mess with the 302 and just swap in a built 351.

 

Be careful with cam selection when using the GT40 or GT40P heads. If you get a cam that requires the use of rocker arm studs the heads will need to be machined for them adding to the cost. IMO, If you need to get GT40 series heads milled for studs, valve job, decked, port, polish, etc, etc you might's well just go the extra mile and get a set of aftermarket aluminum heads as (at that point) the added performance will outweigh the small additional costs. More of a mild cam and pedestal mount roller rockers can keep the costs way down with your GT40 heads. The explorer valve springs are noted to not be the best with larger cam profiles as well if that's what your GT heads are off of. The main hangup with the P heads is the spark plug angle thus giving header fitment problems. I see where many users have gotten around this with 90* spark plug boots though.

 

If you plan on installing big meats you'll never really be satisfied with the power 302 cubic inches produces so I'd suggest you start thinking about making it a 347 stroker or swap in a 351. The 347 route has it's advantages, one being that the stock truck intake is already plenty big enough to feed it so that's something you won't need to upgrade. That also means you can use all the existing accessory brackets and you won't have to modify the exhaust to accomdate the wider 351 motor.
But then a 351 has a substantially stronger block and already has the displacement you need so you have almost unlimited upgrade potential and can instead focus on the topend parts.. which all have to be replaced to reach full potential power.

But before getting too far into the motor we really need to know if your truck is mass air or not. If it is then you're good to go but if not then you are going to be severly limited in what you can do without a mass air conversion, and that isn't a small problem because you also have a computer controlled transmission.

 

The motor is mass air so I'm good to go there

What type of rockers does my truck have now? I was planning on using those on the gt40's.

All the head work was going to be done by a friend of mine so their wont be much cost there at all hopefully.

Conanski the biggest tired that will ever be on my truck will probably be 33's possibly 35's but for now I'm sticking with the 31's for a few years. I will look into a stroker though. My main reasoning for my initial plan was to keep costs down but I've never really looked into a stroker either so I will do that later tonight. But for now I would really like to stick with the 302 I already have.

I don't quite understand the whole rocker thing that fungus has mentioned? If I get too big of a cam will I need a different type? I'm not really wanting to go with an aftermarket rocker set yet.

 

If you have mass air, and you want power, then here you go.

You're getting headers so don't worry about the difference in width of the 351.

Gt40 heads. If you get p heads make sure your headers work with the strait sparkplug. ( that's the difference between p and non p heads)
Port and polish the heads. And get larger valves put in them. Get the valves online and it will save tons of money.

Swap in a 351. It's not hard. Other then flywheel/flexplate, everything is the same. The acessories bolt to the heads, so width isn't an issue again.
eBay has cheap 393 stroker kits that are balanced already. For quick bolt in CID.
Don't worry about what people say about crappy head flow. Your only gonna rev this thing to 5k. They will be plenty for what you want.

Get a mustang (lightning) style 351 intake and tb
30lb injectors
80mm maf

Go get a custom chip made for the truck and have a fun driver that will do whatever you want.
I wish I had the 4r70w. I love that trans. I'm stuck with sd and e4od. I'll be doing exactly what I just told you.... Soon as I get that econo dd car like you just got.

 

When you're shopping for cams just pay attention to the remarks & specs. Some require rocker STUDS. Aftermarket heads come machined for studs already. Your stock heads (or stock GT40/ 40P heads) come with PEDESTAL mount rockers. If you get a cam that requires studs, you have to have the "pedestals" on the heads machined for studs which will in turn require you to buy studs, stud mount rocker arms & new valve springs (you should put new springs on to match your new cam anyway). Best thing to do would be to call one of the cam mfg tech line and tell them what you're wanting to do and they'll recommend a suitable cam for you based on what you want to run ie; stockish heads/ rockers.

 

Awhhh I see. Swapping in a 351 is out of the question. I'm going to use the 302.

 

All this talk about the rockers is a bit unnecessary IMO because neither the stock or GT40 heads benefit from cams with more than about 0.500" lift, and given this is a truck motor it's not likely it'll see the extreme rpms a drag race engine would so super stiff springs won't be needed either. So for the type of cams that this motor will likely see the stock pedistal setup is going to be more than sufficient.

Given this is supposed to be a budget build I'm gonna caution you about sinking any serious amount of money into GT40 heads, it's real easy to blow a lot of $$ with bigger valves and porting and all that and that's not money well spent, unless your friend doing the porting has a CNC milling machine he simply isn't going to improve them much and for a little over $1000 you can have fully assembled RHS or Dart iron heads that will outperform your fully ported GT40s by a mile.

Concerning the intake what you're going to find is that's it's really pretty good as cast, the only portion that really needs attention are the exits of the ports in the lower section, these narrow down the last inch or so before the gasket surface and become a choke point so port matching(not gasket matching) them to the heads is recommended. But otherwise these ports flow about 200cfm as they stand and it's not hard to get upwards of 250cfm with a little work and that will exceed even the most expertly ported GT40 heads. The stock twin throttlebodies are also equavelent to a 75mm single which will support 450hp so you also have lots of room to grow there without spending any money.

Another thing to note is that with the 302 most of the extra HP is above 2500rpm so appropriate axle gearing is an integral part of the package, for a truck with 33's you should have 4.10's minimum and 4.56's wouldn't be out of line. That also means that the cam should target that rpm range so I'd suggest the Comp 35-320-8, it "only" produces 0.512" lift with the stock 1.6 rockers but that's more than sufficient to get 100% from the heads so there's no need to use 1.7s. This cam also leaves you room to grow with the potential for 350-400hp with better heads and a stroker kit down the road, and it should make every bit of 300hp with GT40 heads.

 

Thanks for the reply conanski.

With that cam you mentioned would I need to replace anything else? Will the springs and everything else be okay? Do you recommend I replace anything else while I'm in there?

 

Just put boost to it. More power when you need it... Stock driveability when you don't.

 

That's a bit out of budget..

 

Keep that shift kit at stage 1, you won't like driving that truck with a stage 2, i've read lots of complains here about the lurching/jumps on the getting go and gear changes that will be very discomfortable, even with a stage 1.

 

Will do. I was debating etween the two anyway!

 

I always think different then others.
I have all the tools and equip to do this in my shop.
And with access to a water jet, flanges are quick.
Building turbo manifolds are a day job and welding it is another few hours.
As far as cost... eBay is my friend. Turbo is 100-150. MSD btm is affordable and the fmu is cheap last I checked.

Or porting heads, afternoon job. Stainless Valves are around 110 and the machine shop charged me 250$ last time I had them put in.

Really as far as power for money. Buy a 351, swap the cam and be done. It's only the extra cost of the motor and if your not gonna build a stroker motor, your setting yourself up for disappointment. I already have a 351 and I'm disappointed. At least you're ahead and have mass air.

 

alright a few more things. ive been reading and looking at the comp 35-320-8 and everywhere says its for 1.7 rockers and one place even said stiffer springs were needed?

also i got on camquest and what about the comp 35-552-8? it has less lift but a tad bit more duration on the exhaust side i believe.