1976 390 specs
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
1976 390 specs
Hey there, I have a 1976 f100 with a 390 fe in it. It’s the original motor. I have 2 questions
1) what’s the stock horsepower and torque rating?
2) what do you guys think the horsepower and torque numbers are now?
its got a 750cfm 4 barrel edelbrock sittin on a performer rpm intake, manifold to true dual exhaust, and a hei style distributor.
Jared
1) what’s the stock horsepower and torque rating?
2) what do you guys think the horsepower and torque numbers are now?
its got a 750cfm 4 barrel edelbrock sittin on a performer rpm intake, manifold to true dual exhaust, and a hei style distributor.
Jared
Super Moderator
Joined: Apr 2004
Posts: 34,526
Likes: 2,829
HP ratings changed to Net in '72, so this always causes some long discussion:
https://www.ford-trucks.com/forums/8...ck-enigne.html
Truck 390s have sunken pistons and low compression.
Your mods may be worth some power, but how is the rest of the engine? If your motor has low cylinder pressure on one or more holes, you may be below the stock numbers.
https://www.ford-trucks.com/forums/8...ck-enigne.html
Truck 390s have sunken pistons and low compression.
Your mods may be worth some power, but how is the rest of the engine? If your motor has low cylinder pressure on one or more holes, you may be below the stock numbers.
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
HP ratings changed to Net in '72, so this always causes some long discussion:
https://www.ford-trucks.com/forums/8...ck-enigne.html
Truck 390s have sunken pistons and low compression.
Your mods may be worth some power, but how is the rest of the engine? If your motor has low cylinder pressure on one or more holes, you may be below the stock numbers.
https://www.ford-trucks.com/forums/8...ck-enigne.html
Truck 390s have sunken pistons and low compression.
Your mods may be worth some power, but how is the rest of the engine? If your motor has low cylinder pressure on one or more holes, you may be below the stock numbers.
assuming i I have good compression, what do you think I’m pushing? 230, 240hp? Truck also as 4.10s and a posi, I know that doesn’t add horsepower but helps off the line for sure
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
yeah ive heard that from a few people and haven’t been able to get it to run quite right. It sat for 7 years so I rebuilt the carb on it but still isn’t quite where I want it. Tomorrow I’m getting a 650cfm edelbrock which should do the trick
Logistics Pro
Joined: Jan 2011
Posts: 4,762
Likes: 54
From: Antelope Valley ,CA
carb ,manifold and exhaust not going to make huge number changes on a otherwise stock truck motor . if your lucky probably 220
cam and compression is where the real hp and tq gains are
cam and compression is where the real hp and tq gains are
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
The 750 is only too big if it's got mechanical secondaries. If it's a vacuum sec carb, it's fine. You won't see much difference downsizing to a 650. Don't know about tuning those carbs, but with a Holley you can tailor the secondary opening to fit the engine's needs. I've run a 3310 Holley 750 on an Explorer 302 and it ran fine with it. It only used the flow it needed with it's vacuum secondaries.
Trending Topics
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
4.10's multiply the torque which is the same as adding HP
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
The 750 is only too big if it's got mechanical secondaries. If it's a vacuum sec carb, it's fine. You won't see much difference downsizing to a 650. Don't know about tuning those carbs, but with a Holley you can tailor the secondary opening to fit the engine's needs. I've run a 3310 Holley 750 on an Explorer 302 and it ran fine with it. It only used the flow it needed with it's vacuum secondaries.
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
I'd agree, you likely added 10-15 HP with the upgrades. Nothing earth shattering and likely hard to measure(we're talking about a 10% increase). These were horribly detuned smog motors.
That 750 will work, since it is basically a 375 cfm 2bbl and only gives you more fuel when the motor needs it(once secondaries are tuned properly). Not sure I would put a 650 DP on it. Even with the 4.10 gears, it might not accelerate fast enough and just feel lazy if you go WOT at too low of RPM. It might "sound" like its doing something, but I bet if you actually timed it you would not see an improvement.
Just my .02
What is your timing curve like? Initial, total?
That 750 will work, since it is basically a 375 cfm 2bbl and only gives you more fuel when the motor needs it(once secondaries are tuned properly). Not sure I would put a 650 DP on it. Even with the 4.10 gears, it might not accelerate fast enough and just feel lazy if you go WOT at too low of RPM. It might "sound" like its doing something, but I bet if you actually timed it you would not see an improvement.
Just my .02
What is your timing curve like? Initial, total?
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
Not sure how Edelbrock measures CFM on their carbs, but with a 750 Holley, the primary side is equivalent to a 500 cfm 2 bbl. Holley 2 bbls are rated at 3" HG drop, 4 bbls are rated at 1.5"HG. The Holley 500 cfm is basically the primary side of a 750 DP 4 bbl. Same throttle bores and throttle blade diameter.
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
I'd agree, you likely added 10-15 HP with the upgrades. Nothing earth shattering and likely hard to measure(we're talking about a 10% increase). These were horribly detuned smog motors.
That 750 will work, since it is basically a 375 cfm 2bbl and only gives you more fuel when the motor needs it(once secondaries are tuned properly). Not sure I would put a 650 DP on it. Even with the 4.10 gears, it might not accelerate fast enough and just feel lazy if you go WOT at too low of RPM. It might "sound" like its doing something, but I bet if you actually timed it you would not see an improvement.
Just my .02
What is your timing curve like? Initial, total?
That 750 will work, since it is basically a 375 cfm 2bbl and only gives you more fuel when the motor needs it(once secondaries are tuned properly). Not sure I would put a 650 DP on it. Even with the 4.10 gears, it might not accelerate fast enough and just feel lazy if you go WOT at too low of RPM. It might "sound" like its doing something, but I bet if you actually timed it you would not see an improvement.
Just my .02
What is your timing curve like? Initial, total?
it it was last set at 12 BTC
Thread Starter
|
Tuned
Joined: Oct 2013
Posts: 348
Likes: 2
From: British colombia
Not sure how Edelbrock measures CFM on their carbs, but with a 750 Holley, the primary side is equivalent to a 500 cfm 2 bbl. Holley 2 bbls are rated at 3" HG drop, 4 bbls are rated at 1.5"HG. The Holley 500 cfm is basically the primary side of a 750 DP 4 bbl. Same throttle bores and throttle blade diameter.
Thread
Thread Starter
Forum
Replies
Last Post
72sportcustom3906.4l
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
6
Apr 28, 2009 09:15 PM
Caleb1
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
11
Apr 15, 2009 02:31 PM
DJOHNSTON78
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
8
Dec 6, 2007 05:49 PM
nate76
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
1
Sep 22, 2003 10:38 AM
squirlyboy
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
9
Apr 10, 2003 05:40 PM