390 high performance truck cam help!!!!
 

i have a 1976 f150 4x4 i have had it for a while now and i have done alot to it. i bought a 390 crate engine for it but i made the mistake of having them put the comp cams mutha thumpr in it, and it is a dog, the engine is rated at 422 hp, but this cam is making it feel like the stock360 that was in the truck before. what i need to find is a cam that will be great for pulling a sled, and stumps! but still streetable. i want alot of torque, the truck has a rebuilt c6 with a 2500 stall and a brand new tci valve body, stock np205 transfer case, the gear ratio in the axles are stock probably 3.70. but since im running 33 inch tires i want to put 4.10s in it for more torque. i was thinking about the comp cams 280h (comp suggested that i use that cam), does anyone have any experience with this cam?. but anyways here is the ad for the engine that i have. it was built by tuff dawg engines.

This Ford 390 turnkey crate engine by Tuff Dawg Engines would be EXCELLENT for a street/strip car, street rod, pickup, or your daily driver. Remove that old Ford 352, Ford 360, or Ford 390 and install this 422HP Ford 390 to bring your ride to life! This Ford 390 is a direct bolt-in, no modifications are needed! This Ford 390 does not just have horsepower, it also has 465 ft lbs of torque at 4000rpm to really push you back in the drivers seat! If using a A/T a 2400 stall speed torque converter works best. This engine will run on leaded or unleaded Premium fuel.


The balanced rotating assembly (typically includes crankshaft, pistons, rings, connecting rods, rod bearings, and balancer) featured in this engine:

• 3.780" stroke nodular iron crank
• 6.488" big beam forged rods with ARP rod bolts
• 9½ to 1 compression pistons

More special features of this engine include:

• Seasoned 2-bolt main block
• Deck head gasket surface on block to ensure a good seal
• New Edelbrock Aluminum Heads made from A356 aluminum that are 18lbs lighter than the cast iron heads with 2.090"Int/1.650"Exh swirl polished stainless 1-pc valves
• These Edelbrock Aluminum heads come with both 8-bolt and 16-bolt "CJ" exhaust bolt patterns. (Note: These heads DO NOT come with the 14-bolt "GT" exhaust bolt pattern)
• New Hardened exhaust seats for use with leaded or unleaded fuel
• New high performance springs set up to match cam
• New Bronze valve guides for better oil retention
• New Perfect Circle rings
• New Double row timing set
• New Oil pump with steel drive shaft and bolt on oil pickup tube
• New Brass expansion plugs
• New Edelbrock Performer RPM aluminum intake manifold. This dual plane intake constant cross-sectional area design builds low end and mid-range acceleration while optimized runner path make top-end hp
• For those of you that have the hood clearance we will include a 2" high intake to carb spacer to increase plenum volume. This spacer increases the carb-to-plenum floor distance which atomizes the fuel better and also enhances low-rpm torque and throttle response. This engine takes a square bore carb. It has an Edelbrock 750 cfm carburetor
• All parts are painted separately before assembly for that show quality look

This engine comes completely assembled with Edelbrock aluminum heads, oil pan, timing cover, harmonic balancer, valve covers, and intake manifold.
This Is A Real Turnkey Engine

This engine has been started on gas and run. The camshaft has been broken in and the valves adjusted. Carburetor and timing has been initially set, but should be checked after installing in vehicle.


Also included and installed on engine:

• 4 barrel carb
• Mechanical fuel pump
• Chrome air cleaner
• Fuel filter
• Electronic distributor and coil
• Spark plugs and spark plug wires
• Water pump
• Crankshaft and water pump pulleys
• Alternator with bracket and alternator belt
• Starter
• Water outlet and thermostat
• Starter alignment plate for back of block
• A/T Flexplate with bolts
• This engine has been started on gas and run. Carburetor and timing has been initially set, but should be checked after installing in vehicle.

If you guys have any questions please ask cause i really need some help with this.

Thanks alot!!
Nick
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What camshaft did they use to get their rated 422 hp?

they use the 33-248-4, XE274H by comp cams, i dont know if that would be the absolute best cam for what i want though, and thats why i called comp and asked what they would suggest.

Are you certain the tuning is correct?
examples: Distributor advance curve, carb tuning, etc etc.
Initial timing in particular can be the difference between "barely getting off the line" and "leaves two pretty black marks where the truck once was"

I'd put my 320hp (just a guess) 390 against any badly tuned 422hp 390 :-)

I don't see why that XE274H wouldn't be fine with your setup. I also don't run 33inch tires, I'd suspect you'd want something to help the truck get rolling as a priority. Maybe I don't understand your chosen usage, but realistically a truck runs from idle-4500rpms. I'd have everything setup for that range.

Good luck!

If you go to FORDFE.com and post this you should get a good deal of help there. A few top FE engine builders are on there everyday like Barry and Brent that'd help you out.

I'd suggest a cam like the comp268H (Not the extreme) or the comp 270H Magnum. The comp270 is praised on the Fe site for it's ability to retain good low end for a truck, but still pull to a little over 5k rpm. It's the cam that was suggested for my 390 in my F100 4x4 and it's what I'll go with whenever I build my engine.

I'll second the timing and carb tuning though. I've had timing curve issues in the past and the timing didn't start advancing soon enough and my truck was a dog. That and I had nothing but problems off of the line with edelbrock carbs. I put a 750 holley on it and adjusted a few things and it feels like a whole new engine.

There are a few mutha thmpr cams for the FE , do you know which one they used ?

The seller builds engines, and not based on a host's parameters. I question a lot of what they claim they put in it as my 352 kit came from them and cheap it was. I didnt see adj valve train listed but they say they adj the valves upon breaking in the cam. Unless they went roller, or OEM/AFTMKT adjstbls the only adj is done at assembly.

I suspect they set the dist up with a typical coin toss spring option, and adv tang local. (No reference to your host's requirements) I'd follow the advice already given and review the dist status in leu of re-cam'ing an FE "ANY DAY"

PS: Thumper is a name for rabbit not a truck cam, and the story goes... the turtle won.

Yeah i already know that i chose the wrong cam. and NW 150 if your suggesting the 270h, then why cant go up one more step and go with the 280h? i mean i have a 2500 stall convertor im going to have 4.11 gears ect. ect. and as for the cam thats in it now, the timing is just the way it was supposed to be and i exchanged the jets, springs, and needles in the carb to make the best power (which still isnt doing the trick). ITS THE CAM!!!!!

I looked up the specs on the thumpr cams , they are not great cams but they still will make good power .
I would look into fine tuning this before swapping cams

if i do something i do it right, if i dont do it right the first time, then i re-do it. if its not a great cam and im willing to swap cams, then it should be changed, and i am going to change it. i just need cam suggestions here!

problem is if engine is not tuned right engine is not making proper power .
swap the cam and tune still not right same problem just different cam and more $ for nothing

i had the engine builder in town tune the engine himself, and it ran better then when i got it, but its not good for what i want it for. He knows his s**t too. but when he heard that i put the muther thumper in it and he looked at the numbers for it, he said i shot myself in the foot putting that cam in there. and i want to listen to him

for cam choice only you can pick what's right for you .
try this it's free , you have to give them your info but no harm done .
put in your engine and pick diffent cam profile till you see something you like .
CamQuest ? Select The Perfect Camshaft & Valve Train Components
or you can spend $49 at amazon for Desktop Dyno 5 it's a great Dyno sim to help build an engine

ok thanks alot i'll look into both of those things.

So ask him which cam to put in.

Only other advice I have to give, which has served me well through many years of wrenching for a living: "Make no assumptions"